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Shoda C, Lee D, Miwa Y, Yamagami S, Nakashizuka H, Nimura K, Okamoto K, Kawagishi H, Negishi K, Kurihara T. Inhibition of hypoxia-inducible factors suppresses subretinal fibrosis. FASEB J 2024; 38:e23792. [PMID: 38953555 DOI: 10.1096/fj.202400540rrr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 06/15/2024] [Accepted: 06/24/2024] [Indexed: 07/04/2024]
Abstract
Age-related macular degeneration (AMD) is a common cause of vision loss. The aggressive form of AMD is associated with ocular neovascularization and subretinal fibrosis, representing a responsive outcome against neovascularization mediated by epithelial-mesenchymal transition of retinal pigment epithelium (RPE) cells. A failure of the current treatment (anti-vascular endothelial growth factor therapy) has also been attributed to the progression of subretinal fibrosis. Hypoxia-inducible factors (HIFs) increase gene expressions to promote fibrosis and neovascularization. HIFs act as a central pathway in the pathogenesis of AMD. HIF inhibitors may suppress ocular neovascularization. Nonetheless, further investigation is required to unravel the aspects of subretinal fibrosis. In this study, we used RPE-specific HIFs or von Hippel-Lindau (VHL, a regulator of HIFs) conditional knockout (cKO) mice, along with pharmacological HIF inhibitors, to demonstrate the suppression of subretinal fibrosis. Fibrosis was suppressed by treatments of HIF inhibitors, and similar suppressive effects were detected in RPE-specific Hif1a/Hif2a- and Hif1a-cKO mice. Promotive effects were observed in RPE-specific Vhl-cKO mice, where fibrosis-mediated pathologic processes were evident. Marine products' extracts and their component taurine suppressed fibrosis as HIF inhibitors. Our study shows critical roles of HIFs in the progression of fibrosis, linking them to the potential development of therapeutics for AMD.
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Affiliation(s)
- Chiho Shoda
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo, Japan
- Ophthalmology, Keio University School of Medicine, Tokyo, Japan
- Ophthalmology, Nihon University School of Medicine, Tokyo, Japan
| | - Deokho Lee
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo, Japan
- Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Yukihiro Miwa
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo, Japan
- Ophthalmology, Keio University School of Medicine, Tokyo, Japan
- Aichi Animal Eye Clinic, Nagoya, Aichi, Japan
| | - Satoru Yamagami
- Ophthalmology, Nihon University School of Medicine, Tokyo, Japan
| | | | - Kazumi Nimura
- Shizuoka Prefectural Research Institute of Fishery and Ocean, Shizuoka, Japan
| | - Kazutoshi Okamoto
- Shizuoka Prefectural Research Institute of Fishery and Ocean, Shizuoka, Japan
- Marine Open Innovation Institute, Shizuoka, Japan
| | - Hirokazu Kawagishi
- Faculty of Agriculture, Shizuoka University, Shizuoka, Japan
- Research Institute for Mushroom Science, Shizuoka University, Shizuoka, Japan
| | - Kazuno Negishi
- Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Toshihide Kurihara
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo, Japan
- Ophthalmology, Keio University School of Medicine, Tokyo, Japan
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Chen M, Wang Y, Dalal R, Du J, Vollrath D. Alternative oxidase blunts pseudohypoxia and photoreceptor degeneration due to RPE mitochondrial dysfunction. Proc Natl Acad Sci U S A 2024; 121:e2402384121. [PMID: 38865272 PMCID: PMC11194566 DOI: 10.1073/pnas.2402384121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 05/15/2024] [Indexed: 06/14/2024] Open
Abstract
Loss of mitochondrial electron transport complex (ETC) function in the retinal pigment epithelium (RPE) in vivo results in RPE dedifferentiation and progressive photoreceptor degeneration, and has been implicated in the pathogenesis of age-related macular degeneration. Xenogenic expression of alternative oxidases in mammalian cells and tissues mitigates phenotypes arising from some mitochondrial electron transport defects, but can exacerbate others. We expressed an alternative oxidase from Ciona intestinalis (AOX) in ETC-deficient murine RPE in vivo to assess the retinal consequences of stimulating coenzyme Q oxidation and respiration without ATP generation. RPE-restricted expression of AOX in this context is surprisingly beneficial. This focused intervention mitigates RPE mTORC1 activation, dedifferentiation, hypertrophy, stress marker expression, pseudohypoxia, and aerobic glycolysis. These RPE cell autonomous changes are accompanied by increased glucose delivery to photoreceptors with attendant improvements in photoreceptor structure and function. RPE-restricted AOX expression normalizes accumulated levels of succinate and 2-hydroxyglutarate in ETC-deficient RPE, and counteracts deficiencies in numerous neural retinal metabolites. These features can be attributed to the activation of mitochondrial inner membrane flavoproteins such as succinate dehydrogenase and proline dehydrogenase, and alleviation of inhibition of 2-oxyglutarate-dependent dioxygenases such as prolyl hydroxylases and epigenetic modifiers. Our work underscores the importance to outer retinal health of coenzyme Q oxidation in the RPE and identifies a metabolic network critical for photoreceptor survival in the context of RPE mitochondrial dysfunction.
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Affiliation(s)
- Ming Chen
- Department of Genetics, Stanford University School of Medicine, Palo Alto, CA94305
| | - Yekai Wang
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV26506
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV26506
| | - Roopa Dalal
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA94305
| | - Jianhai Du
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV26506
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV26506
| | - Douglas Vollrath
- Department of Genetics, Stanford University School of Medicine, Palo Alto, CA94305
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA94305
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Yue T, Guo Y, Qi X, Zheng W, Zhang H, Wang B, Liu K, Zhou B, Zeng X, Ouzhuluobu, He Y, Su B. Sex-biased regulatory changes in the placenta of native highlanders contribute to adaptive fetal development. eLife 2024; 12:RP89004. [PMID: 38869160 PMCID: PMC11175615 DOI: 10.7554/elife.89004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2024] Open
Abstract
Compared with lowlander migrants, native Tibetans have a higher reproductive success at high altitude though the underlying mechanism remains unclear. Here, we compared the transcriptome and histology of full-term placentas between native Tibetans and Han migrants. We found that the placental trophoblast shows the largest expression divergence between Tibetans and Han, and Tibetans show decreased immune response and endoplasmic reticulum stress. Remarkably, we detected a sex-biased expression divergence, where the male-infant placentas show a greater between-population difference than the female-infant placentas. The umbilical cord plays a key role in the sex-biased expression divergence, which is associated with the higher birth weight of the male newborns of Tibetans. We also identified adaptive histological changes in the male-infant placentas of Tibetans, including larger umbilical artery wall and umbilical artery intima and media, and fewer syncytial knots. These findings provide valuable insights into the sex-biased adaptation of human populations, with significant implications for medical and genetic studies of human reproduction.
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Affiliation(s)
- Tian Yue
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of SciencesKunmingChina
- Kunming College of Life Science, University of Chinese Academy of SciencesBeijingChina
| | - Yongbo Guo
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of SciencesKunmingChina
- Kunming College of Life Science, University of Chinese Academy of SciencesBeijingChina
| | - Xuebin Qi
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of SciencesKunmingChina
- Fukang Obstetrics, Gynecology and Children Branch Hospital, Tibetan Fukang HospitalKunmingChina
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and TechnologyKunmingChina
| | - Wangshan Zheng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of SciencesKunmingChina
| | - Hui Zhang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of SciencesKunmingChina
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and TechnologyKunmingChina
| | - Bin Wang
- Fukang Obstetrics, Gynecology and Children Branch Hospital, Tibetan Fukang HospitalKunmingChina
| | - Kai Liu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of SciencesKunmingChina
| | - Bin Zhou
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of SciencesKunmingChina
- Kunming College of Life Science, University of Chinese Academy of SciencesBeijingChina
| | - Xuerui Zeng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of SciencesKunmingChina
- Kunming College of Life Science, University of Chinese Academy of SciencesBeijingChina
| | - Ouzhuluobu
- Fukang Obstetrics, Gynecology and Children Branch Hospital, Tibetan Fukang HospitalKunmingChina
| | - Yaoxi He
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of SciencesKunmingChina
| | - Bing Su
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of SciencesKunmingChina
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of SciencesKunmingChina
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Kaufmann M, Han Z. RPE melanin and its influence on the progression of AMD. Ageing Res Rev 2024; 99:102358. [PMID: 38830546 DOI: 10.1016/j.arr.2024.102358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 05/27/2024] [Indexed: 06/05/2024]
Abstract
OBJECTIVE The aim of this review article is to summarize the latest findings and current understanding of the origin of melanin in the retinal pigment epithelium (RPE), its function within the RPE, its role in the pathogenesis of age-related macular degeneration (AMD), its effect on retinal development, and its potential therapeutic benefit in the treatment of AMD. METHODS A comprehensive search of peer-reviewed journals was conducted using various combinations of key terms such as "melanin," "retinal pigment epithelium" or "RPE," "age-related macular degeneration" or AMD," "lipofuscin," "oxidative stress," and "albinism." Databases searched include PubMed, Scopus, Science Direct, and Google Scholar. 147 papers published between the years of 1957 and 2023 were considered with an emphasis on recent findings. SUMMARY OF FINDINGS AMD is thought to result from chronic oxidative stress within the RPE that results in cellular dysfunction, metabolic dysregulation, inflammation, and lipofuscin accumulation. Melanin functions as a photoscreener, free radical scavenger, and metal cation binding reservoir within the RPE. RPE melanin does not regenerate, and it undergoes degradation over time in response to chronic light exposure and oxidative stress. RPE melanin is important for retinal development and RPE function, and in the aging eye, melanin loss is associated with increased lipid peroxidation, inflammation, and the accumulation of toxic oxidized cellular products. Therefore, melanin-based treatments may serve to preserve RPE and retinal function in AMD. CONCLUSIONS The pathogenesis of AMD is not fully understood, but RPE dysfunction and melanin loss in response to chronic oxidative stress and inflammation are thought to be primary drivers of the disease. Due to melanin's antioxidative effects, melanin-based nanotechnology represents a promising avenue for the treatment of AMD.
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Affiliation(s)
- Mary Kaufmann
- University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Zongchao Han
- Department of Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Division of Pharmacoengineering & Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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Ban N, Shinojima A, Negishi K, Kurihara T. Drusen in AMD from the Perspective of Cholesterol Metabolism and Hypoxic Response. J Clin Med 2024; 13:2608. [PMID: 38731137 PMCID: PMC11084323 DOI: 10.3390/jcm13092608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 04/15/2024] [Accepted: 04/23/2024] [Indexed: 05/13/2024] Open
Abstract
Drusen are one of the most characteristic pathologies of precursor lesion of age-related macular degeneration (AMD). Drusen comprise a yellowish white substance that accumulates typically under the retinal pigment epithelium (RPE), and their constituents are lipids, complement, amyloid, crystallin, and others. In the past, many researchers have focused on drusen and tried to elucidate the pathophysiology of AMD because they believed that disease progression from early AMD to advanced AMD might be based on drusen or drusen might cause AMD. In fact, it is well established that drusen are the hallmark of precursor lesion of AMD and a major risk factor for AMD progression mainly based on their size and number. However, the existence of advanced AMD without drusen has long been recognized. For example, polypoidal choroidal vasculopathy (PCV), which comprises the majority of AMD cases in Asians, often lacks drusen. Thus, there is the possibility that drusen might be no more than a biomarker of AMD and not a cause of AMD. Now is the time to reconsider the relationship between AMD and drusen. In this review, we focus on early AMD pathogenesis based on basic research from the perspective of cholesterol metabolism and hypoxic response in the retina, and we discuss the role of drusen.
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Affiliation(s)
- Norimitsu Ban
- Laboratory of Aging and Retinal Biology, Keio University School of Medicine, Tokyo 160-8582, Japan;
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.S.); (K.N.)
| | - Ari Shinojima
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.S.); (K.N.)
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kazuno Negishi
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.S.); (K.N.)
| | - Toshihide Kurihara
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.S.); (K.N.)
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan
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Parain K, Chesneau A, Locker M, Borday C, Perron M. Regeneration from three cellular sources and ectopic mini-retina formation upon neurotoxic retinal degeneration in Xenopus. Glia 2024; 72:759-776. [PMID: 38225726 DOI: 10.1002/glia.24502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 12/20/2023] [Accepted: 12/22/2023] [Indexed: 01/17/2024]
Abstract
Regenerative abilities are not evenly distributed across the animal kingdom. The underlying modalities are also highly variable. Retinal repair can involve the mobilization of different cellular sources, including ciliary marginal zone (CMZ) stem cells, the retinal pigmented epithelium (RPE), or Müller glia. To investigate whether the magnitude of retinal damage influences the regeneration modality of the Xenopus retina, we developed a model based on cobalt chloride (CoCl2 ) intraocular injection, allowing for a dose-dependent control of cell death extent. Analyses in Xenopus laevis revealed that limited CoCl2 -mediated neurotoxicity only triggers cone loss and results in a few Müller cells reentering the cell cycle. Severe CoCl2 -induced retinal degeneration not only potentializes Müller cell proliferation but also enhances CMZ activity and unexpectedly triggers RPE reprogramming. Surprisingly, reprogrammed RPE self-organizes into an ectopic mini-retina-like structure laid on top of the original retina. It is thus likely that the injury paradigm determines the awakening of different stem-like cell populations. We further show that these cellular sources exhibit distinct neurogenic capacities without any bias towards lost cells. This is particularly striking for Müller glia, which regenerates several types of neurons, but not cones, the most affected cell type. Finally, we found that X. tropicalis also has the ability to recruit Müller cells and reprogram its RPE following CoCl2 -induced damage, whereas only CMZ involvement was reported in previously examined degenerative models. Altogether, these findings highlight the critical role of the injury paradigm and reveal that three cellular sources can be reactivated in the very same degenerative model.
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Affiliation(s)
- Karine Parain
- CNRS, Institut des Neurosciences Paris-Saclay, Université Paris-Saclay, Saclay, France
| | - Albert Chesneau
- CNRS, Institut des Neurosciences Paris-Saclay, Université Paris-Saclay, Saclay, France
| | - Morgane Locker
- CNRS, Institut des Neurosciences Paris-Saclay, Université Paris-Saclay, Saclay, France
| | - Caroline Borday
- CNRS, Institut des Neurosciences Paris-Saclay, Université Paris-Saclay, Saclay, France
| | - Muriel Perron
- CNRS, Institut des Neurosciences Paris-Saclay, Université Paris-Saclay, Saclay, France
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7
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Nakai A, Lee D, Shoda C, Negishi K, Nakashizuka H, Yamagami S, Kurihara T. Modulation of Hypoxia-Inducible Factors and Vascular Endothelial Growth Factor Expressions by Superfood Camu-Camu ( Myrciaria dubia) Treatment in ARPE-19 and Fetal Human RPE Cells. J Ophthalmol 2023; 2023:6617981. [PMID: 38187496 PMCID: PMC10771337 DOI: 10.1155/2023/6617981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 11/30/2023] [Accepted: 12/15/2023] [Indexed: 01/09/2024] Open
Abstract
Background Anti-vascular endothelial growth factor (anti-VEGF) therapy via intravitreal injection is an effective treatment for patients with abnormal ocular neovascularization, such as age-related macular degeneration (AMD) and diabetic macular edema (DME). However, prolonged and frequent anti-VEGF treatment is associated with a risk of local and systemic adverse events, including geographic atrophy, cerebrovascular disease, and death. Furthermore, some patients do not adequately respond to anti-VEGF therapy. Hypoxia-inducible factor (HIF) is a transcription factor that controls the expression of hypoxia-responsive genes involved in angiogenesis, inflammation, and metabolism. The HIF/VEGF pathway plays an important role in neovascularization, and the inhibition of HIF activation could be an effective biomolecular target for neovascular diseases. The demand for disease prevention or treatment using functional foods such as superfoods has increased in recent years. Few reports to date have focused on the antineovascular effects of superfoods in the retinal pigment epithelium (RPE). In light of the growing demand for functional foods, we aimed to find novel HIF inhibitors from superfoods worked in RPE cells, which could be an adjuvant for anti-VEGF therapy. Methods Seven superfoods were examined to identify novel HIF inhibitor candidates using luciferase assay screening. We used the human RPE cell line ARPE-19 and fetal human RPE (fhRPE) to investigate the biomolecular actions of novel HIF inhibitors using quantitative PCR and western blotting. Results Under CoCl2-induced pseudohypoxic condition and 1% oxygen hypoxic incubation, camu-camu (Myrciaria dubia) showed HIF inhibitory effects determined by luciferase assays. Camu-camu downregulated HIF-1α and VEGFA mRNA expressions in a concentration-dependent manner. Camu-camu also inhibited HIF-1α protein expressions, and its inhibitory effect was greater than that of vitamin C, which is present at high levels in camu-camu. Conclusion The camu-camu extract suppressed the activation of HIF and VEGF in RPE cells. This could assist anti-VEGF therapy in patients with abnormal ocular neovascularization.
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Affiliation(s)
- Ayaka Nakai
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo, Japan
- Ophthalmology, Keio University School of Medicine, Tokyo, Japan
- Ophthalmology, Nihon University School of Medicine, Tokyo, Japan
| | - Deokho Lee
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo, Japan
- Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Chiho Shoda
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo, Japan
- Ophthalmology, Keio University School of Medicine, Tokyo, Japan
- Ophthalmology, Nihon University School of Medicine, Tokyo, Japan
| | - Kazuno Negishi
- Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | | | - Satoru Yamagami
- Ophthalmology, Nihon University School of Medicine, Tokyo, Japan
| | - Toshihide Kurihara
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo, Japan
- Ophthalmology, Keio University School of Medicine, Tokyo, Japan
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Babapoor-Farrokhran S, Qin Y, Flores-Bellver M, Niu Y, Bhutto IA, Aparicio-Domingo S, Guo C, Rodrigues M, Domashevich T, Deshpande M, Megarity H, Chopde R, Eberhart CG, Canto-Soler V, Montaner S, Sodhi A. Pathologic vs. protective roles of hypoxia-inducible factor 1 in RPE and photoreceptors in wet vs. dry age-related macular degeneration. Proc Natl Acad Sci U S A 2023; 120:e2302845120. [PMID: 38055741 PMCID: PMC10723156 DOI: 10.1073/pnas.2302845120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 09/20/2023] [Indexed: 12/08/2023] Open
Abstract
It has previously been reported that antioxidant vitamins can help reduce the risk of vision loss associated with progression to advanced age-related macular degeneration (AMD), a leading cause of visual impairment among the elderly. Nonetheless, how oxidative stress contributes to the development of choroidal neovascularization (CNV) in some AMD patients and geographic atrophy (GA) in others is poorly understood. Here, we provide evidence demonstrating that oxidative stress cooperates with hypoxia to synergistically stimulate the accumulation of hypoxia-inducible factor (HIF)-1α in the retinal pigment epithelium (RPE), resulting in increased expression of the HIF-1-dependent angiogenic mediators that promote CNV. HIF-1 inhibition blocked the expression of these angiogenic mediators and prevented CNV development in an animal model of ocular oxidative stress, demonstrating the pathological role of HIF-1 in response to oxidative stress stimulation in neovascular AMD. While human-induced pluripotent stem cell (hiPSC)-derived RPE monolayers exposed to chemical oxidants resulted in disorganization and disruption of their normal architecture, RPE cells proved remarkably resistant to oxidative stress. Conversely, equivalent doses of chemical oxidants resulted in apoptosis of hiPSC-derived retinal photoreceptors. Pharmacologic inhibition of HIF-1 in the mouse retina enhanced-while HIF-1 augmentation reduced-photoreceptor apoptosis in two mouse models for oxidative stress, consistent with a protective role for HIF-1 in photoreceptors in patients with advanced dry AMD. Collectively, these results suggest that in patients with AMD, increased expression of HIF-1α in RPE exposed to oxidative stress promotes the development of CNV, but inadequate HIF-1α expression in photoreceptors contributes to the development of GA.
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Affiliation(s)
| | - Yu Qin
- Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD21287
- Department of Ophthalmology, The Fourth Affiliated Hospital of China Medical University, Shenyang110005, China
- Department of Ophthalmology, Eye Hospital of China Medical University, Shenyang110005, China
- Key Lens Research Laboratory of Liaoning Province, Shenyang110005, China
| | - Miguel Flores-Bellver
- CellSight Ocular Stem Cell and Regeneration Research Program, Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, University of Colorado School of Medicine, Aurora, CO80045
| | - Yueqi Niu
- Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD21287
| | - Imran A. Bhutto
- Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD21287
| | - Silvia Aparicio-Domingo
- CellSight Ocular Stem Cell and Regeneration Research Program, Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, University of Colorado School of Medicine, Aurora, CO80045
| | - Chuanyu Guo
- Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD21287
| | - Murilo Rodrigues
- Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD21287
| | - Timothy Domashevich
- CellSight Ocular Stem Cell and Regeneration Research Program, Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, University of Colorado School of Medicine, Aurora, CO80045
| | - Monika Deshpande
- Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD21287
| | - Haley Megarity
- Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD21287
| | - Rakesh Chopde
- Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD21287
| | - Charles G. Eberhart
- Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD21287
| | - Valeria Canto-Soler
- CellSight Ocular Stem Cell and Regeneration Research Program, Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, University of Colorado School of Medicine, Aurora, CO80045
| | - Silvia Montaner
- Department of Oncology and Diagnostic Sciences, Greenebaum Cancer Center, University of Maryland, Baltimore, MD21201
| | - Akrit Sodhi
- Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD21287
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9
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Rajala RVS, Rajala A. Unlocking the role of lactate: metabolic pathways, signaling, and gene regulation in postmitotic retinal cells. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1296624. [PMID: 38983010 PMCID: PMC11182115 DOI: 10.3389/fopht.2023.1296624] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 10/19/2023] [Indexed: 07/11/2024]
Abstract
The Warburg effect, which was first described a century ago, asserts that mitotic tumor cells generate higher quantities of lactate. Intriguingly, even in typical physiological circumstances, postmitotic retinal photoreceptor cells also produce elevated levels of lactate. Initially classified as metabolic waste, lactate has since gained recognition as a significant intracellular signaling mediator and extracellular ligand. This current review endeavors to provide a concise overview and discourse on the following topics: the localization of lactate-producing enzymes, the functional significance of these enzymes, the signaling functions of lactate, and its impact on the gene expression of photoreceptors in retinal cells.
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Affiliation(s)
- Raju V. S. Rajala
- Departments of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Departments of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Departments of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Dean McGee Eye Institute, Oklahoma City, OK, United States
| | - Ammaji Rajala
- Departments of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
- Dean McGee Eye Institute, Oklahoma City, OK, United States
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10
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Cristante E, Liyanage SE, Smith AJ, Ali RR, Bainbridge JWB. Role of HIF1α and HIF2α in Cre Recombinase-Induced Retinal Pigment Epithelium Pathology and Its Secondary Effect on Choroidal Neovascularization. THE AMERICAN JOURNAL OF PATHOLOGY 2023; 193:1694-1705. [PMID: 37330004 DOI: 10.1016/j.ajpath.2023.05.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 05/09/2023] [Accepted: 05/19/2023] [Indexed: 06/19/2023]
Abstract
CreTrp1 mice are widely used for conditional retinal pigment epithelium (RPE) gene function studies. Like other Cre/LoxP models, phenotypes in CreTrp1 mice can be affected by Cre-mediated cellular toxicity, leading to RPE dysfunction, altered morphology and atrophy, activation of innate immunity, and consequent impairment of photoreceptor function. These effects are common among the age-related alterations of RPE that feature in early/intermediate forms of age-related macular degeneration. This article characterizes Cre-mediated pathology in the CreTrp1 line to elucidate the impact of RPE degeneration on both developmental and pathologic choroidal neovascularization. Nonredundant roles of the two major components of the hypoxia-inducible factor (HIF) family of transcription regulators, HIF1α and HIF2α, were identified. Genetic ablation of Hif1a protected against Cre-induced degeneration of RPE and choroid, whereas ablation of Hif2a exacerbated this degeneration. Furthermore, HIF1α deficiency protected CreTrp1 mice against laser-induced choroidal neovascularization, whereas HIF2α deficiency exacerbated the phenotype. Cre-mediated degeneration of the RPE in CreTrp1 mice offers an opportunity to investigate the impact of hypoxia signaling in the context of RPE degeneration. These findings indicate that HIF1α promotes Cre recombinase-mediated RPE degeneration and laser-induced choroidal neovascularization, whereas HIF2α is protective.
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Affiliation(s)
| | | | - Alexander J Smith
- Centre for Cell and Gene Therapy, King's College London, Guy's Hospital, London, United Kingdom
| | - Robin R Ali
- Centre for Cell and Gene Therapy, King's College London, Guy's Hospital, London, United Kingdom
| | - James W B Bainbridge
- UCL Institute of Ophthalmology London, United Kingdom; NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom.
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11
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Kaur B, Miglioranza Scavuzzi B, F Abcouwer S, N Zacks D. A simplified protocol to induce hypoxia in a standard incubator: A focus on retinal cells. Exp Eye Res 2023; 236:109653. [PMID: 37793495 PMCID: PMC10732591 DOI: 10.1016/j.exer.2023.109653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/11/2023] [Accepted: 09/14/2023] [Indexed: 10/06/2023]
Abstract
Hypoxia chambers have traditionally been used to induce hypoxia in cell cultures. Cellular responses to hypoxia can also be mimicked with the use of chemicals such as cobalt chloride (CoCl2), which stabilizes hypoxia-inducible factor alpha-subunit proteins. In studies of ocular cells using primary cells and cell lines, such as Müller glial cell (MGC) lines, photoreceptor cell lines, retinal pigment epithelial (RPE) cell lines and retinoblastoma cell lines oxygen levels employed in hypoxia chambers range typically between 0.2% and 5% oxygen. For chemical induction of hypoxic response in these cells, the CoCl2 concentrations used typically range from 100 to 600 μM. Here, we describe simplified protocols for stabilizing cellular hypoxia-inducible factor-1α (HIF-1α) in cell culture using either a hypoxia chamber or CoCl2. In addition, we also provide a detailed methodology to confirm hypoxia induction by the assessment of protein levels of HIF-1α, which accumulates in response to hypoxic conditions. Furthermore, we provide a summary of conditions applied in previous studies of ocular cells.
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Affiliation(s)
- Bhavneet Kaur
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Bruna Miglioranza Scavuzzi
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Steven F Abcouwer
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - David N Zacks
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA.
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12
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Hass DT, Zhang Q, Autterson GA, Bryan RA, Hurley JB, Miller JML. Medium Depth Influences O2 Availability and Metabolism in Human RPE Cultures. Invest Ophthalmol Vis Sci 2023; 64:4. [PMID: 37922158 PMCID: PMC10629522 DOI: 10.1167/iovs.64.14.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Accepted: 10/13/2023] [Indexed: 11/05/2023] Open
Abstract
Purpose Retinal pigment epithelium (RPE) oxidative metabolism is critical for normal retinal function and is often studied in cell culture systems. Here, we show that conventional culture media volumes dramatically impact O2 availability, limiting oxidative metabolism. We suggest optimal conditions to ensure cultured RPE is in a normoxic environment permissive to oxidative metabolism. Methods We altered the availability of O2 to human primary and induced pluripotent stem cell-derived RPE cultures directly via a hypoxia chamber or indirectly via the amount of medium over cells. We measured oxygen consumption rates (OCRs), glucose consumption, lactate production, 13C6-glucose and 13C5-glutamine flux, hypoxia inducible factor 1α (HIF-1α) stability, intracellular lipid droplets after a lipid challenge, transepithelial electrical resistance, cell morphology, and pigmentation. Results Medium volumes commonly employed during RPE culture limit diffusion of O2 to cells, triggering hypoxia, activating HIF-1α, limiting OCR, and dramatically altering cell metabolism, with only minor effects on typical markers of RPE health. Media volume effects on O2 availability decrease acetyl-CoA utilization, increase glycolysis and reductive carboxylation, and alter the size and number of intracellular lipid droplets under lipid-rich conditions. Conclusions Despite having little impact on visible and typical markers of RPE culture health, media volume dramatically affects RPE physiology "under the hood." As RPE-centric diseases like age-related macular degeneration involve oxidative metabolism, RPE cultures need to be optimized to study such diseases. We provide guidelines for optimal RPE culture volumes that balance ample nutrient availability from larger media volumes with adequate O2 availability seen with smaller media volumes.
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Affiliation(s)
- Daniel T. Hass
- Department of Biochemistry, The University of Washington, Seattle, Washington, United States
| | - Qitao Zhang
- Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | | | | | - James B. Hurley
- Department of Biochemistry, The University of Washington, Seattle, Washington, United States
| | - Jason M. L. Miller
- Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, United States
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13
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Henning Y, Willbrand K, Larafa S, Weißenberg G, Matschke V, Theiss C, Görtz GE, Matschke J. Cigarette smoke causes a bioenergetic crisis in RPE cells involving the downregulation of HIF-1α under normoxia. Cell Death Discov 2023; 9:398. [PMID: 37880219 PMCID: PMC10600121 DOI: 10.1038/s41420-023-01695-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/03/2023] [Accepted: 10/16/2023] [Indexed: 10/27/2023] Open
Abstract
Age-related macular degeneration (AMD) is the most common blinding disease in the elderly population. However, there are still many uncertainties regarding the pathophysiology at the molecular level. Currently, impaired energy metabolism in retinal pigment epithelium (RPE) cells is discussed as one major hallmark of early AMD pathophysiology. Hypoxia-inducible factors (HIFs) are important modulators of mitochondrial function. Moreover, smoking is the most important modifiable risk factor for AMD and is known to impair mitochondrial integrity. Therefore, our aim was to establish a cell-based assay that enables us to investigate how smoking affects mitochondrial function in conjunction with HIF signaling in RPE cells. For this purpose, we treated a human RPE cell line with cigarette smoke extract (CSE) under normoxia (21% O2), hypoxia (1% O2), or by co-treatment with Roxadustat, a clinically approved HIF stabilizer. CSE treatment impaired mitochondrial integrity, involving increased mitochondrial reactive oxygen species, disruption of mitochondrial membrane potential, and altered mitochondrial morphology. Treatment effects on cell metabolism were analyzed using a Seahorse Bioanalyzer. Mitochondrial respiration and ATP production were impaired in CSE-treated cells under normoxia. Surprisingly, CSE-treated RPE cells also exhibited decreased glycolytic rate under normoxia, causing a bioenergetic crisis, because two major metabolic pathways that provide ATP were impaired by CSE. Downregulation of glycolytic rate was HIF-dependent because HIF-1α, the α-subunit of HIF-1, was downregulated by CSE on the protein level, especially under normoxia. Moreover, hypoxia incubation and treatment with Roxadustat restored glycolytic flux. Taken together, our in vitro model provides interesting insights into HIF-dependent regulation of glycolysis under normoxic conditions, which will enable us to investigate signaling pathways involved in RPE metabolism in health and disease.
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Affiliation(s)
- Yoshiyuki Henning
- Institute of Physiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
| | - Katrin Willbrand
- Institute of Physiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Safa Larafa
- Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Gesa Weißenberg
- Institute of Physiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Veronika Matschke
- Department of Cytology, Institute of Anatomy, Ruhr University Bochum, Bochum, Germany
| | - Carsten Theiss
- Department of Cytology, Institute of Anatomy, Ruhr University Bochum, Bochum, Germany
| | - Gina-Eva Görtz
- Molecular Ophthalmology, Department of Ophthalmology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Johann Matschke
- Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
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14
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Jiménez-Loygorri JI, Benítez-Fernández R, Viedma-Poyatos Á, Zapata-Muñoz J, Villarejo-Zori B, Gómez-Sintes R, Boya P. Mitophagy in the retina: Viewing mitochondrial homeostasis through a new lens. Prog Retin Eye Res 2023; 96:101205. [PMID: 37454969 DOI: 10.1016/j.preteyeres.2023.101205] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 07/11/2023] [Accepted: 07/13/2023] [Indexed: 07/18/2023]
Abstract
Mitochondrial function is key to support metabolism and homeostasis in the retina, an organ that has one of the highest metabolic rates body-wide and is constantly exposed to photooxidative damage and external stressors. Mitophagy is the selective autophagic degradation of mitochondria within lysosomes, and can be triggered by distinct stimuli such as mitochondrial damage or hypoxia. Here, we review the importance of mitophagy in retinal physiology and pathology. In the developing retina, mitophagy is essential for metabolic reprogramming and differentiation of retina ganglion cells (RGCs). In basal conditions, mitophagy acts as a quality control mechanism, maintaining a healthy mitochondrial pool to meet cellular demands. We summarize the different autophagy- and mitophagy-deficient mouse models described in the literature, and discuss the potential role of mitophagy dysregulation in retinal diseases such as glaucoma, diabetic retinopathy, retinitis pigmentosa, and age-related macular degeneration. Finally, we provide an overview of methods used to monitor mitophagy in vitro, ex vivo, and in vivo. This review highlights the important role of mitophagy in sustaining visual function, and its potential as a putative therapeutic target for retinal and other diseases.
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Affiliation(s)
- Juan Ignacio Jiménez-Loygorri
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
| | - Rocío Benítez-Fernández
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; Departament of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, 1700, Fribourg, Switzerland
| | - Álvaro Viedma-Poyatos
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Juan Zapata-Muñoz
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Beatriz Villarejo-Zori
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Raquel Gómez-Sintes
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Patricia Boya
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; Departament of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, 1700, Fribourg, Switzerland.
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15
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Xu W, Liu X, Han W, Wu K, Zhao M, Mei T, Shang B, Wu J, Luo J, Lai Y, Yang B, Zhuo Y, Lu L, Liu Y, Tian XL, Zhao L. Inhibiting HIF-1 signaling alleviates HTRA1-induced RPE senescence in retinal degeneration. Cell Commun Signal 2023; 21:134. [PMID: 37316948 DOI: 10.1186/s12964-023-01138-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/22/2023] [Indexed: 06/16/2023] Open
Abstract
BACKGROUND Age-related macular degeneration (AMD), characterized by the degeneration of retinal pigment epithelium (RPE) and photoreceptors, is the leading cause of irreversible vision impairment among the elderly. RPE senescence is an important contributor to AMD and has become a potential target for AMD therapy. HTRA1 is one of the most significant susceptibility genes in AMD, however, the correlation between HTRA1 and RPE senescence hasn't been investigated in the pathogenesis of AMD. METHODS Western blotting and immunohistochemistry were used to detect HTRA1 expression in WT and transgenic mice overexpressing human HTRA1 (hHTRA1-Tg mice). RT-qPCR was used to detect the SASP in hHTRA1-Tg mice and ARPE-19 cells infected with HTRA1. TEM, SA-β-gal was used to detect the mitochondria and senescence in RPE. Retinal degeneration of mice was investigated by fundus photography, FFA, SD-OCT and ERG. The RNA-Seq dataset of ARPE-19 cells treated with adv-HTRA1 versus adv-NC were analyzed. Mitochondrial respiration and glycolytic capacity in ARPE-19 cells were measured using OCR and ECAR. Hypoxia of ARPE-19 cells was detected using EF5 Hypoxia Detection Kit. KC7F2 was used to reduce the HIF1α expression both in vitro and in vivo. RESULTS In our study, we found that RPE senescence was facilitated in hHTRA1-Tg mice. And hHTRA1-Tg mice became more susceptible to NaIO3 in the development of oxidative stress-induced retinal degeneration. Similarly, overexpression of HTRA1 in ARPE-19 cells accelerated cellular senescence. Our RNA-seq revealed an overlap between HTRA1-induced differentially expressed genes associated with aging and those involved in mitochondrial function and hypoxia response in ARPE-19 cells. HTRA1 overexpression in ARPE-19 cells impaired mitochondrial function and augmented glycolytic capacity. Importantly, upregulation of HTRA1 remarkably activated HIF-1 signaling, shown as promoting HIF1α expression which mainly located in the nucleus. HIF1α translation inhibitor KC7F2 significantly prevented HTRA1-induced cellular senescence in ARPE-19 cells, as well as improved the visual function in hHTRA1-Tg mice treated with NaIO3. CONCLUSIONS Our study showed elevated HTRA1 contributes to the pathogenesis of AMD by promoting cellular senescence in RPE through damaging mitochondrial function and activating HIF-1 signaling. It also pointed out that inhibition of HIF-1 signaling might serve as a potential therapeutic strategy for AMD. Video Abstract.
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Affiliation(s)
- Wenchang Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
| | - Xinqi Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
| | - Wenjuan Han
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
| | - Keling Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
| | - Minglei Zhao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
| | - Tingfang Mei
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Bizhi Shang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
| | - Jinwen Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
| | - Jingyi Luo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
| | - Yuhua Lai
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
| | - Boyu Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
| | - Yehong Zhuo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
| | - Lin Lu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
| | - Yizhi Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China
- Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
- Research Unit of Ocular Development and Regeneration, Chinese Academy of Medical Sciences, Guangzhou, China
| | - Xiao-Li Tian
- Aging and Vascular Diseases, Human Aging Research Institute (HARI), School of Life Science, Jiangxi Key Laboratory of Human Aging, Nanchang University, Nanchang, China
| | - Ling Zhao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, 510060, China.
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16
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Jung E, Kim YE, Jeon HS, Yoo M, Kim M, Kim YM, Koh SH, Choi YK. Chronic hypoxia of endothelial cells boosts HIF-1α-NLRP1 circuit in Alzheimer's disease. Free Radic Biol Med 2023:S0891-5849(23)00427-6. [PMID: 37245530 DOI: 10.1016/j.freeradbiomed.2023.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/09/2023] [Accepted: 05/12/2023] [Indexed: 05/30/2023]
Abstract
Cerebral microvasculature of patients with Alzheimer's disease (AD) exhibits reduced capillary diameter and impaired blood flow. Molecular mechanisms of ischemic vessels affecting AD progressions have not been well established yet. In the present study, we found that in vivo triple (PS1M146V, APPswe, tauP301L) transgenic AD mouse model (3x-Tg AD) brains and retinas showed hypoxic vessels expressing hypoxyprobe and hypoxia inducible factor-1α (HIF-1α). To mimic in vivo hypoxic vessels, we used in vitro oxygen-glucose deprivation (OGD)-treated endothelial cells. HIF-1α protein was increased through reactive oxygen species (ROS) producing NADPH oxidases (NOX) (i.e., Nox2, Nox4). OGD-induced HIF-1α upregulated Nox2 and Nox4, demonstrating crosstalk between HIF-1α and NOX (i.e., Nox2, Nox4). Interestingly, NLR family pyrin domain containing 1 (NLRP1) protein was promoted by OGD, and such effect was blocked by downregulation of Nox4 and HIF-1α. Knockdown of NLRP1 also diminished OGD-mediated protein levels of Nox2, Nox4, and HIF-1α in human brain microvascular endothelial cells. These results showed interplay among HIF-1α, Nox4 and NLRP1 in OGD-treated endothelial cells. Expression of NLRP3 was not detected well in hypoxic endothelial cells of 3x-Tg AD retinas or OGD-treated endothelial cells. Instead, hypoxic endothelial cells of 3x-Tg AD brains and retinas markedly expressed NLRP1, the adaptor molecule apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, and interleukin-1β (IL-1β). Taken together, our results suggest that AD brains and retinas can trigger chronic hypoxia especially in microvascular endothelial cells, consequently leading to NLRP1 inflammasome formation and upregulation of ASC-caspase-1-IL-1β cascades. In addition, NLRP1 can stimulate HIF-1α expression and form HIF-1α-NLRP1 circuit. These consequences might further destroy vascular system in AD.
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Affiliation(s)
- Eunyoung Jung
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Ye Eun Kim
- Department of Neurology, Hanyang University Guri Hospital, Guri, 11923, Republic of Korea
| | - Hui Su Jeon
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Myeongjong Yoo
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Minsu Kim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Young-Myeong Kim
- Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chuncheon, Kangwon-do, 24341, Republic of Korea
| | - Seong-Ho Koh
- Department of Neurology, Hanyang University Guri Hospital, Guri, 11923, Republic of Korea.
| | - Yoon Kyung Choi
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea.
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17
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Eade KT, Ansell BRE, Giles S, Fallon R, Harkins-Perry S, Nagasaki T, Tzaridis S, Wallace M, Mills EA, Farashi S, Johnson A, Sauer L, Hart B, Diaz-Rubio ME, Bahlo M, Metallo C, Allikmets R, Gantner ML, Bernstein PS, Friedlander M. iPSC-derived retinal pigmented epithelial cells from patients with macular telangiectasia show decreased mitochondrial function. J Clin Invest 2023; 133:e163771. [PMID: 37115691 PMCID: PMC10145939 DOI: 10.1172/jci163771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 03/14/2023] [Indexed: 04/29/2023] Open
Abstract
Patient-derived induced pluripotent stem cells (iPSCs) provide a powerful tool for identifying cellular and molecular mechanisms of disease. Macular telangiectasia type 2 (MacTel) is a rare, late-onset degenerative retinal disease with an extremely heterogeneous genetic architecture, lending itself to the use of iPSCs. Whole-exome sequencing screens and pedigree analyses have identified rare causative mutations that account for less than 5% of cases. Metabolomic surveys of patient populations and GWAS have linked MacTel to decreased circulating levels of serine and elevated levels of neurotoxic 1-deoxysphingolipids (1-dSLs). However, retina-specific, disease-contributing factors have yet to be identified. Here, we used iPSC-differentiated retinal pigmented epithelial (iRPE) cells derived from donors with or without MacTel to screen for novel cell-intrinsic pathological mechanisms. We show that MacTel iRPE cells mimicked the low serine levels observed in serum from patients with MacTel. Through RNA-Seq and gene set enrichment pathway analysis, we determined that MacTel iRPE cells are enriched in cellular stress pathways and dysregulation of central carbon metabolism. Using respirometry and mitochondrial stress testing, we functionally validated that MacTel iRPE cells had a reduction in mitochondrial function that was independent of defects in serine biosynthesis and 1-dSL accumulation. Thus, we identified phenotypes that may constitute alternative disease mechanisms beyond the known serine/sphingolipid pathway.
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Affiliation(s)
- Kevin T. Eade
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Brendan Robert E. Ansell
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Sarah Giles
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Regis Fallon
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Sarah Harkins-Perry
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Takayuki Nagasaki
- Department of Ophthalmology and
- Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
| | - Simone Tzaridis
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Martina Wallace
- Institute of Food and Health, School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Elizabeth A. Mills
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Samaneh Farashi
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Alec Johnson
- The Lowy Medical Research Institute, La Jolla, California, USA
| | - Lydia Sauer
- Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Barbara Hart
- Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - M. Elena Diaz-Rubio
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
| | - Melanie Bahlo
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Christian Metallo
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
| | - Rando Allikmets
- Department of Ophthalmology and
- Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
| | - Marin L. Gantner
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Paul S. Bernstein
- Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Martin Friedlander
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
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18
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Sun R, Zhu H, Wang Y, Wang J, Jiang C, Cao Q, Zhang Y, Zhang Y, Yuan S, Liu Q. Circular RNA expression and the competitive endogenous RNA network in pathological, age-related macular degeneration events: A cross-platform normalization study. J Biomed Res 2023; 37:367-381. [PMID: 37366063 PMCID: PMC10541779 DOI: 10.7555/jbr.37.20230010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/20/2023] [Accepted: 02/20/2023] [Indexed: 06/28/2023] Open
Abstract
Age-related macular degeneration (AMD) causes irreversible blindness in people aged over 50 worldwide. The dysfunction of the retinal pigment epithelium is the primary cause of atrophic AMD. In the current study, we used the ComBat and Training Distribution Matching method to integrate data obtained from the Gene Expression Omnibus database. We analyzed the integrated sequencing data by the Gene Set Enrichment Analysis. Peroxisome and tumor necrosis factor-α (TNF-α) signaling and nuclear factor kappa B (NF-κB) were among the top 10 pathways, and thus we selected them to construct AMD cell models to identify differentially expressed circular RNAs (circRNAs). We then constructed a competing endogenous RNA network, which is related to differentially expressed circRNAs. This network included seven circRNAs, 15 microRNAs, and 82 mRNAs. The Kyoto Encyclopedia of Genes and Genomes analysis of mRNAs in this network showed that the hypoxia-inducible factor-1 (HIF-1) signaling pathway was a common downstream event. The results of the current study may provide insights into the pathological processes of atrophic AMD.
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Affiliation(s)
- Ruxu Sun
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Hongjing Zhu
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Ying Wang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Jianan Wang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Chao Jiang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Qiuchen Cao
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Yeran Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Yichen Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Songtao Yuan
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Qinghuai Liu
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, Jiangsu 211166, China
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19
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Hass DT, Zhang Q, Autterson G, Bryan R, Hurley JB, Miller JM. Medium depth influences O 2 availability and metabolism in cultured RPE cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.01.530623. [PMID: 36909658 PMCID: PMC10002737 DOI: 10.1101/2023.03.01.530623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
PURPOSE RPE oxidative metabolism is critical for normal retinal function and is often studied in cell culture systems. Here, we show that conventional culture media volumes dramatically impact O 2 availability, limiting oxidative metabolism. We suggest optimal conditions to ensure cultured RPE is in a normoxic environment permissive to oxidative metabolism. METHODS We altered the availability of O 2 to human primary RPE cultures directly via a hypoxia chamber or indirectly via the amount of medium over cells. We measured oxygen consumption rates (OCR), glucose consumption, lactate production, 13 C-glucose flux, hypoxia inducible factor (HIF-1α) stability, intracellular lipid droplets after a lipid challenge, trans-epithelial electrical resistance, cell morphology, and pigmentation. RESULTS Medium volumes commonly employed during RPE culture limit diffusion of O 2 to cells, triggering hypoxia, activating HIF-1α, limiting OCR, and dramatically altering cell metabolism, with only minor effects on typical markers of RPE health. Media volume effects on O 2 availability decrease acetyl-CoA utilization, increase glycolysis, and alter the size and number of intracellular lipid droplets under lipid-rich conditions. CONCLUSIONS Despite having little impact on visible and typical markers of RPE culture health, media volume dramatically affects RPE physiology ″under the hood″. As RPE-centric diseases like age-related macular degeneration (AMD) involve oxidative metabolism, RPE cultures need to be optimized to study such diseases. We provide guidelines for optimal RPE culture volumes that balance ample nutrient availability from larger media volumes with adequate O 2 availability seen with smaller media volumes.
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20
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Molecular and Cellular Regulations in the Development of the Choroidal Circulation System. Int J Mol Sci 2023; 24:ijms24065371. [PMID: 36982446 PMCID: PMC10048934 DOI: 10.3390/ijms24065371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/09/2023] [Accepted: 03/09/2023] [Indexed: 03/18/2023] Open
Abstract
Disorders in the development and regulation of blood vessels are involved in various ocular disorders, such as persistent hyperplastic primary vitreous, familial exudative vitreoretinopathy, and choroidal dystrophy. Thus, the appropriate regulation of vascular development is essential for healthy ocular functions. However, regulation of the developing choroidal circulation system has not been well studied compared with vascular regulation in the vitreous and the retina. The choroid is a vascular-rich and uniquely structured tissue supplying oxygen and nutrients to the retina, and hypoplasia and the degeneration of the choroid are involved in many ocular disorders. Therefore, understanding the developing choroidal circulation system expands our knowledge of ocular development and supports our understanding of ocular disorders. In this review, we examine studies on regulating the developing choroidal circulation system at the cellular and molecular levels and discuss the relevance to human diseases.
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21
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Hypoxia-induced transcriptional differences in African and Asian versus European diabetic cybrids. Sci Rep 2023; 13:3818. [PMID: 36882486 PMCID: PMC9992459 DOI: 10.1038/s41598-023-30518-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 02/24/2023] [Indexed: 03/09/2023] Open
Abstract
Diabetic retinopathy (DR) is the most common diabetic microvascular complication and cause of blindness in adults under the age of 65. Our results suggest that, when comparing transcriptomes of cultures grown in hypoxic conditions versus room-air, cybrids containing mitochondria from African and Asian diabetic subjects ([Afr + Asi]/DM) have some uniquely different transcriptome profiles compared to European/diabetic (Euro/DM) cybrids (e.g., fatty acid metabolism: EnrichR rank 10 in [Afr + Asi]/DM, rank 85 in Euro/DM; Endocytosis: rank 25 in [Afr + Asi]/DM, rank 5 in Euro/DM; Ubiquitin Mediated Proteolysis: rank 34 in [Afr + Asi]/DM, rank 7 in Euro/DM). As determined by both RNA-seq and qRT-PCR results, transcription of the gene encoding oleoyl-ACP hydrolase (OLAH) was significantly increased in [Afr + Asi]/DM cybrids compared to Euro/DM cybrids in hypoxic conditions. Additionally, our results show that in hypoxic conditions, Euro/DM cybrids and [Afr + Asi]/DM cybrids show similar decreases in ROS production. All cybrids showed decreased ZO1-minus protein levels, but their phagocytic functions were not significantly altered in hypoxic conditions. In conclusion, our findings suggest that the "molecular memory" imparted by [Afr + Asi]/DM mtDNA may act through one of the molecular pathways seen in transcriptome analysis, such as fatty acid metabolism, without significantly changing essential RPE functions.
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22
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Ramírez-Pardo I, Villarejo-Zori B, Jiménez-Loygorri JI, Sierra-Filardi E, Alonso-Gil S, Mariño G, de la Villa P, Fitze PS, Fuentes JM, García-Escudero R, Ferrington DA, Gomez-Sintes R, Boya P. Ambra1 haploinsufficiency in CD1 mice results in metabolic alterations and exacerbates age-associated retinal degeneration. Autophagy 2023; 19:784-804. [PMID: 35875981 PMCID: PMC9980615 DOI: 10.1080/15548627.2022.2103307] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Macroautophagy/autophagy is a key process in the maintenance of cellular homeostasis. The age-dependent decline in retinal autophagy has been associated with photoreceptor degeneration. Retinal dysfunction can also result from damage to the retinal pigment epithelium (RPE), as the RPE-retina constitutes an important metabolic ecosystem that must be finely tuned to preserve visual function. While studies of mice lacking essential autophagy genes have revealed a predisposition to retinal degeneration, the consequences of a moderate reduction in autophagy, similar to that which occurs during physiological aging, remain unclear. Here, we described a retinal phenotype consistent with accelerated aging in mice carrying a haploinsufficiency for Ambra1, a pro-autophagic gene. These mice showed protein aggregation in the retina and RPE, metabolic underperformance, and premature vision loss. Moreover, Ambra1+/gt mice were more prone to retinal degeneration after RPE stress. These findings indicate that autophagy provides crucial support to RPE-retinal metabolism and protects the retina against stress and physiological aging.Abbreviations : 4-HNE: 4-hydroxynonenal; AMBRA1: autophagy and beclin 1 regulator 1, AMD: age-related macular degeneration;; GCL: ganglion cell layer; GFAP: glial fibrillary acidic protein; GLUL: glutamine synthetase/glutamate-ammonia ligase; HCL: hierarchical clustering; INL: inner nuclear layer; IPL: inner plexiform layer; LC/GC-MS: liquid chromatography/gas chromatography-mass spectrometry; MA: middle-aged; MTDR: MitoTracker Deep Red; MFI: mean fluorescence intensity; NL: NH4Cl and leupeptin; Nqo: NAD(P)H quinone dehydrogenase; ONL: outer nuclear layer; OPL: outer plexiform layer; OP: oscillatory potentials; OXPHOS: oxidative phosphorylation; PCR: polymerase chain reaction; PRKC/PKCα: protein kinase C; POS: photoreceptor outer segment; RGC: retinal ganglion cells; RPE: retinal pigment epithelium; SI: sodium iodate; TCA: tricarboxylic acid.
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Affiliation(s)
- Ignacio Ramírez-Pardo
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
| | - Beatriz Villarejo-Zori
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
| | - Juan Ignacio Jiménez-Loygorri
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
| | - Elena Sierra-Filardi
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
| | - Sandra Alonso-Gil
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
| | | | - Pedro de la Villa
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Madrid, Spain.,Vision neurophisiology group, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Patrick S Fitze
- Departament of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain
| | - José Manuel Fuentes
- Department of Biochemistry, Molecular Biology and Genetics, Faculty of Nursing and Occupational Therapy, University of Extremadura, Cáceres, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Nerodegenerative Diseases unit, Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Cáceres, Spain
| | - Ramón García-Escudero
- Molecular Oncology Unit, CIEMAT, Madrid, Spain.,Biomedical Research Institute I+12, University Hospital 12 de Octubre, Madrid, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Madrid, Spain
| | - Deborah A Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, USA
| | - Raquel Gomez-Sintes
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
| | - Patricia Boya
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
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23
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Millington-Ward S, Chadderton N, Finnegan LK, Post IJM, Carrigan M, Nixon R, Humphries MM, Humphries P, Kenna PF, Palfi A, Farrar GJ. RPE-Directed Gene Therapy Improves Mitochondrial Function in Murine Dry AMD Models. Int J Mol Sci 2023; 24:ijms24043847. [PMID: 36835257 PMCID: PMC9968062 DOI: 10.3390/ijms24043847] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 02/03/2023] [Accepted: 02/04/2023] [Indexed: 02/17/2023] Open
Abstract
Age-related macular degeneration (AMD) is the most common cause of blindness in the aged population. However, to date there is no effective treatment for the dry form of the disease, representing 85-90% of cases. AMD is an immensely complex disease which affects, amongst others, both retinal pigment epithelium (RPE) and photoreceptor cells and leads to the progressive loss of central vision. Mitochondrial dysfunction in both RPE and photoreceptor cells is emerging as a key player in the disease. There are indications that during disease progression, the RPE is first impaired and RPE dysfunction in turn leads to subsequent photoreceptor cell degeneration; however, the exact sequence of events has not as yet been fully determined. We recently showed that AAV delivery of an optimised NADH-ubiquinone oxidoreductase (NDI1) gene, a nuclear-encoded complex 1 equivalent from S. cerevisiae, expressed from a general promoter, provided robust benefit in a variety of murine and cellular models of dry AMD; this was the first study employing a gene therapy to directly boost mitochondrial function, providing functional benefit in vivo. However, use of a restricted RPE-specific promoter to drive expression of the gene therapy enables exploration of the optimal target retinal cell type for dry AMD therapies. Furthermore, such restricted transgene expression could reduce potential off-target effects, possibly improving the safety profile of the therapy. Therefore, in the current study, we interrogate whether expression of the gene therapy from the RPE-specific promoter, Vitelliform macular dystrophy 2 (VMD2), might be sufficient to rescue dry AMD models.
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Affiliation(s)
- Sophia Millington-Ward
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
- Correspondence:
| | - Naomi Chadderton
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Laura K. Finnegan
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Iris J. M. Post
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Matthew Carrigan
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Rachel Nixon
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Marian M. Humphries
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Pete Humphries
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Paul F. Kenna
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
- The Research Foundation, Royal Victoria Eye and Ear Hospital, D02 XK51 Dublin, Ireland
| | - Arpad Palfi
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - G. Jane Farrar
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
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24
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Kong Y, Liu P, Li Y, Nolan ND, Quinn PMJ, Hsu C, Jenny LA, Zhao J, Cui X, Chang Y, Wert KJ, Sparrow JR, Wang N, Tsang SH. HIF2α activation and mitochondrial deficit due to iron chelation cause retinal atrophy. EMBO Mol Med 2023; 15:e16525. [PMID: 36645044 PMCID: PMC9906391 DOI: 10.15252/emmm.202216525] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 12/10/2022] [Accepted: 12/13/2022] [Indexed: 01/17/2023] Open
Abstract
Iron accumulation causes cell death and disrupts tissue functions, which necessitates chelation therapy to reduce iron overload. However, clinical utilization of deferoxamine (DFO), an iron chelator, has been documented to give rise to systemic adverse effects, including ocular toxicity. This study provided the pathogenic and molecular basis for DFO-related retinopathy and identified retinal pigment epithelium (RPE) as the target tissue in DFO-related retinopathy. Our modeling demonstrated the susceptibility of RPE to DFO compared with the neuroretina. Intriguingly, we established upregulation of hypoxia inducible factor (HIF) 2α and mitochondrial deficit as the most prominent pathogenesis underlying the RPE atrophy. Moreover, suppressing hyperactivity of HIF2α and preserving mitochondrial dysfunction by α-ketoglutarate (AKG) protects the RPE against lesions both in vitro and in vivo. This supported our observation that AKG supplementation alleviates visual impairment in a patient undergoing DFO-chelation therapy. Overall, our study established a significant role of iron deficiency in initiating DFO-related RPE atrophy. Inhibiting HIF2α and rescuing mitochondrial function by AKG protect RPE cells and can potentially ameliorate patients' visual function.
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Affiliation(s)
- Yang Kong
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
| | - Pei‐Kang Liu
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
- Department of OphthalmologyKaohsiung Medical University Hospital, Kaohsiung Medical UniversityKaohsiungTaiwan
- School of Medicine, College of MedicineKaohsiung Medical UniversityKaohsiungTaiwan
- Institute of Biomedical SciencesNational Sun Yat‐sen UniversityKaohsiungTaiwan
| | - Yao Li
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
| | - Nicholas D Nolan
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
- Department of Biomedical Engineering, The Fu Foundation School of Engineering and Applied ScienceColumbia UniversityNew YorkNYUSA
| | - Peter M J Quinn
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
| | - Chun‐Wei Hsu
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
| | - Laura A Jenny
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
| | - Jin Zhao
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
| | - Xuan Cui
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
| | - Ya‐Ju Chang
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
| | - Katherine J Wert
- Departments of Ophthalmology and Molecular BiologyUniversity of Texas Southwestern Medical CenterDallasTXUSA
- The Hamon Center for Regenerative Science and MedicineUniversity of Texas Southwestern Medical CenterDallasTXUSA
| | - Janet R Sparrow
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
| | - Nan‐Kai Wang
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
| | - Stephen H Tsang
- Department of Ophthalmology, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
- Jonas Children's Vision Care, and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Pathology and Cell Biology, Institute of Human Nutrition, Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNYUSA
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25
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Samra YA, Zaidi Y, Rajpurohit P, Raghavan R, Cai L, Kaddour-Djebbar I, Tawfik A. Warburg Effect as a Novel Mechanism for Homocysteine-Induced Features of Age-Related Macular Degeneration. Int J Mol Sci 2023; 24:ijms24021071. [PMID: 36674587 PMCID: PMC9865636 DOI: 10.3390/ijms24021071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/31/2022] [Accepted: 01/02/2023] [Indexed: 01/09/2023] Open
Abstract
Age-related macular degeneration (AMD) is a major cause of blindness. Recent studies have reported impaired glycolysis in AMD patients with a high lactate/pyruvate ratio. Elevated homocysteine (Hcy) (Hyperhomocysteinemia, HHcy) was observed in several clinical studies, reporting an association between HHcy and AMD. We established the effect of HHcy on barrier function, retinal pigment epithelium (RPE) structure, and induced choroidal neovascularization (CNV) in mice. We hypothesize that HHcy contributes to AMD by inducing a metabolic switch in the mitochondria, in which cells predominantly produce energy by the high rate of glycolysis, or "Warburg", effect. Increased glycolysis results in an increased production of lactate, cellular acidity, activation of angiogenesis, RPE barrier dysfunction, and CNV. Evaluation of cellular energy production under HHcy was assessed by seahorse analysis, immunofluorescence, and western blot experiments. The seahorse analysis evaluated the extracellular acidification rate (ECAR) as indicative of glycolysis. HHcy showed a significant increase in ECAR both in vivo using (Cystathionine β-synthase) cbs+/- and cbs-/- mice retinas and in vitro (Hcy-treated ARPE-19) compared to wild-type mice and RPE cells. Moreover, HHcy up-regulated glycolytic enzyme (Glucose transporter-1 (GlUT-1), lactate dehydrogenase (LDH), and hexokinase 1 (HK1)) in Hcy-treated ARPE-19 and primary RPE cells isolated from cbs+/+, cbs+/-, and cbs-/- mice retinas. Inhibition of GLUT-1 or blocking of N-methyl-D-aspartate receptors (NMDAR) reduced glycolysis in Hcy-treated RPE and improved albumin leakage and CNV induction in Hcy-injected mice eyes. The current study suggests that HHcy causes a metabolic switch in the RPE cells from mitochondrial respiration to glycolysis during AMD and confirms the involvement of NMDAR in this process. Therefore, targeting Glycolysis or NMDAR could be a novel therapeutic target for AMD.
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Affiliation(s)
- Yara A. Samra
- Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Yusra Zaidi
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Pragya Rajpurohit
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Raju Raghavan
- Department of Pharmacology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Lun Cai
- Department of Pharmacology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Ismail Kaddour-Djebbar
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Charlie Norwood VA Medical Center, One Freedom Way, Augusta, GA 30904, USA
| | - Amany Tawfik
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, GA 30912, USA
- Eye Research Institute, Oakland University, Rochester, MI 48309-4479, USA
- Eye Research Center (OUWB)/ERC, William Beaumont School of Medicine, Royal Oak, MI 48309-4479, USA
- Correspondence: ; Tel.: +1-248-370-2398; Fax: +1-248-370-4211
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26
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Jiang H, Liu Z, Townsend JH, Wang J. Effects of Methylenetetrahydrofolate Reductase ( MTHFR) Polymorphisms on Retinal Tissue Perfusion in Mild Diabetic Retinopathy Patients Receiving the Medical Food, Ocufolin ®. Clin Ophthalmol 2023; 17:1121-1127. [PMID: 37077224 PMCID: PMC10106310 DOI: 10.2147/opth.s401743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 03/27/2023] [Indexed: 04/21/2023] Open
Abstract
Purpose We evaluate the effects of methylenetetrahydrofolate reductase (MTHFR) polymorphisms on retinal tissue perfusion in patients with mild diabetic retinopathy (DR + PM) taking the medical food, Ocufolin®, for 6 months. Methods Prospective, case-controlled study. Eight early diabetic retinopathy patients with common reduced function MTHFR polymorphisms (DR+PM) and 15 normal controls (NC) were recruited. MTHFR polymorphisms were subtyped as normal, C677T, or A1298C. Best corrected visual acuity (BCVA) was evaluated. Retinal blood flow velocity (BFV) was measured using Retinal Function Imager. Retinal tissue perfusion (RTP, blood flow rate per inner retinal volume) was calculated within a 2.5 mm diameter circle centered on the fovea. The medical food is intended to address ocular ischemia with high doses of vitamin B-complexes and antioxidants, including L-methylfolate, methylcobalamin, zinc, copper, lutein, vitamins C, D, E, and n-acetylcysteine. The subjects were provided with a medical food for a period of 6 months. Results BCVA and vascular indices of DR + PM patients at baseline were initially below those of NC and improved after medical food. Compared to baseline, DR + PM patients after the medical food had significantly improved BCVA during the follow-up period (P < 0.05). In comparison, overall RTP and arteriolar BFV were significantly increased at 6 months (P < 0.05). The changes varied with MTHFR subtypes. In patients with the C677T and the C677T/A1298C compound mutations, RTP was increased at 6 months as compared to that at baseline and 4 months (P < 0.05). In patients with only the A1298C mutation, all microcirculation metrics were increased from baseline at 4 and 6 months, but with less improvement at 6 months than at 4 months (P < 0.05). Conclusion Medical food was effective in improving both visual acuity and retinal tissue perfusion in DR + PM patients. The degree of improvement of retinal microcirculation varied among MTHFR subtypes.
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Affiliation(s)
- Hong Jiang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Zhiping Liu
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Ophthalmic Center, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, People’s Republic of China
| | - Justin H Townsend
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jianhua Wang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Correspondence: Jianhua Wang, Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL, 33136, USA, Tel +1 305 482-5010, Fax +1 305 482-5012, Email
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27
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Theodoridis K, Gika H, Kotali A. Acylcarnitines in Ophthalmology: Promising Emerging Biomarkers. Int J Mol Sci 2022; 23:ijms232416183. [PMID: 36555822 PMCID: PMC9784861 DOI: 10.3390/ijms232416183] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/10/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Several common ocular diseases are leading causes of irreversible visual impairment. Over the last decade, various mainly untargeted metabolic studies have been performed to show that metabolic dysfunction plays an important role in the pathogenesis of ocular diseases. A number of metabolites in plasma/serum, aqueous or vitreous humor, or in tears have been found to differ between patients and controls; among them are L-carnitine and acylcarnitines, which are essential for mitochondrial fatty acid oxidation. The metabolic profile of carnitines regarding a variety of diseases has attracted researchers' interest. In this review, we present and discuss recent advances that have been made in the identification of carnitines as potential metabolic biomarkers in common ocular diseases, such as age-related macular degeneration, diabetic retinopathy, retinopathy of prematurity, central retinal vein occlusion, primary open-angle glaucoma, rhegmatogenous retinal detachment, and dry eye syndrome.
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Affiliation(s)
- Konstantinos Theodoridis
- Laboratory of Organic Chemistry, School of Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
- Laboratory of Forensic Medicine and Toxicology, Medical School, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
- Correspondence:
| | - Helen Gika
- Laboratory of Forensic Medicine and Toxicology, Medical School, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
- Biomic AUTh, Center for Interdisciplinary Research and Innovation (CIRI-AUTH), Balkan Center B1.4, 57001 Thessaloniki, Greece
| | - Antigoni Kotali
- Laboratory of Organic Chemistry, School of Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
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28
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RIP140-Mediated NF-κB Inflammatory Pathway Promotes Metabolic Dysregulation in Retinal Pigment Epithelium Cells. Curr Issues Mol Biol 2022; 44:5788-5801. [DOI: 10.3390/cimb44110393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/09/2022] [Accepted: 11/16/2022] [Indexed: 11/22/2022] Open
Abstract
Metabolic dysregulation of the retinal pigment epithelium (RPE) has been implicated in age-related macular degeneration (AMD). However, the molecular regulation of RPE metabolism remains unclear. RIP140 is known to affect oxidative metabolism and mitochondrial biogenesis by negatively controlling mitochondrial pathways regulated by PPAR-γ co-activator-1 α(PGC-1α). This study aims to disclose the effect of RIP140 on the RPE metabolic program in vitro and in vivo. RIP140 protein levels were assayed by Western blotting. Gene expression was tested using quantitative real-time PCR (qRT-PCR), ATP production, and glycogen concentration assays, and the release of inflammatory factors was analyzed by commercial kits. Mice photoreceptor function was measured by electroretinography (ERG). In ARPE-19 cells, RIP140 overexpression changed the expression of the key metabolic genes and lipid processing genes, inhibited mitochondrial ATP production, and enhanced glycogenesis. Moreover, RIP140 overexpression promoted the translocation of NF-κB and increased the expression and production of IL-1β, IL-6, and TNF-α in ARPE-19 cells. Importantly, we also observed the overexpression of RIP140 through adenovirus delivery in rat retinal cells, which significantly decreased the amplitude of the a-wave and b-wave measured by ERG assay. Therapeutic strategies that modulate the activity of RIP140 could have clinical utility for the treatment of AMD in terms of preventing RPE degeneration.
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Choi YK. An Altered Neurovascular System in Aging-Related Eye Diseases. Int J Mol Sci 2022; 23:ijms232214104. [PMID: 36430581 PMCID: PMC9694120 DOI: 10.3390/ijms232214104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/13/2022] [Accepted: 11/13/2022] [Indexed: 11/18/2022] Open
Abstract
The eye has a complex and metabolically active neurovascular system. Repeated light injuries induce aging and trigger age-dependent eye diseases. Damage to blood vessels is related to the disruption of the blood-retinal barrier (BRB), altered cellular communication, disrupted mitochondrial functions, and exacerbated aggregated protein accumulation. Vascular complications, such as insufficient blood supply and BRB disruption, have been suggested to play a role in glaucoma, age-related macular degeneration (AMD), and Alzheimer's disease (AD), resulting in neuronal cell death. Neuronal loss can induce vision loss. In this review, we discuss the importance of the neurovascular system in the eye, especially in aging-related diseases such as glaucoma, AMD, and AD. Beneficial molecular pathways to prevent or slow down retinal pathologic processes will also be discussed.
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Affiliation(s)
- Yoon Kyung Choi
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029, Republic of Korea
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30
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Harju N. Regulation of oxidative stress and inflammatory responses in human retinal pigment epithelial cells. Acta Ophthalmol 2022; 100 Suppl 273:3-59. [DOI: 10.1111/aos.15275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Niina Harju
- School of Pharmacy University of Eastern Finland Kuopio Finland
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31
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Alderdice R, Perna G, Cárdenas A, Hume BCC, Wolf M, Kühl M, Pernice M, Suggett DJ, Voolstra CR. Deoxygenation lowers the thermal threshold of coral bleaching. Sci Rep 2022; 12:18273. [PMID: 36316371 PMCID: PMC9622859 DOI: 10.1038/s41598-022-22604-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 10/17/2022] [Indexed: 12/02/2022] Open
Abstract
Exposure to deoxygenation from climate warming and pollution is emerging as a contributing factor of coral bleaching and mortality. However, the combined effects of heating and deoxygenation on bleaching susceptibility remain unknown. Here, we employed short-term thermal stress assays to show that deoxygenated seawater can lower the thermal limit of an Acropora coral by as much as 1 °C or 0.4 °C based on bleaching index scores or dark-acclimated photosynthetic efficiencies, respectively. Using RNA-Seq, we show similar stress responses to heat with and without deoxygenated seawater, both activating putative key genes of the hypoxia-inducible factor response system indicative of cellular hypoxia. We also detect distinct deoxygenation responses, including a disruption of O2-dependent photo-reception/-protection, redox status, and activation of an immune response prior to the onset of bleaching. Thus, corals are even more vulnerable when faced with heat stress in deoxygenated waters. This highlights the need to integrate dissolved O2 measurements into global monitoring programs of coral reefs.
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Affiliation(s)
- Rachel Alderdice
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, 2007, Australia.
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany.
| | - Gabriela Perna
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Anny Cárdenas
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Benjamin C C Hume
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Martin Wolf
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Michael Kühl
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000, Helsingør, Denmark
| | - Mathieu Pernice
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - David J Suggett
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, 2007, Australia
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Qi X, Walton DA, Plafker KS, Boulton ME, Plafker SM. Sulforaphane recovers cone function in an Nrf2-dependent manner in middle-aged mice undergoing RPE oxidative stress. Mol Vis 2022; 28:378-393. [PMID: 36338670 PMCID: PMC9603948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 10/14/2022] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Sulforaphane (SFN) is an isothiocyanate derived from cruciferous vegetables that has therapeutic efficacy in numerous animal models of human disease, including mouse models of retinal degeneration. However, despite dozens of clinical trials, the compound remains to be tested as a clinical treatment for ocular disease. Numerous cellular activities of SFN have been identified, including the activation of Nrf2, a transcription factor that induces a battery of target gene products to neutralize oxidative and xenobiotic stresses. As Nrf2 expression and function reportedly decrease with aging, we tested whether the loss of the transcription factor limits the therapeutic efficacy of SFN against retinal degeneration. METHODS Six- to 8-month-old wild-type and Nrf2 knockout mice were treated with SFN beginning 1 month after ribozyme-mediated knockdown of superoxide dismutase 2 (SOD2) mRNA in the RPE. The impacts of MnSOD (the protein product of SOD2) knockdown and the efficacy of SFN were evaluated using a combination of electroretinography (ERG), spectral domain optical coherence tomography (SD-OCT), and postmortem histology. RESULTS SFN restored the ERG photopic b-wave suppressed by MnSOD loss in wild-type mice, but not in the Nrf2 knockout mice. In contrast, ERG scotopic a- and b-wave loss was not restored for either genotype. SFN significantly improved retinal thickness in the Nrf2 knockout mice with MnSOD knockdown, but this was not observed in the wild-type mice. In both genotypes, SFN treatment reduced morphological markers of RPE atrophy and degeneration, although these improvements did not correlate proportionally with functional recovery. CONCLUSIONS These findings highlight the capacity of SFN to preserve cone function, as well as the potential challenges of using the compound as a standalone treatment for age-related retinal degeneration under conditions associated with reduced Nrf2 function.
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Affiliation(s)
- Xiaoping Qi
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham (UAB), Birmingham, AL
| | - Dorothy A. Walton
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK
| | - Kendra S. Plafker
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK
| | - Michael E. Boulton
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham (UAB), Birmingham, AL
| | - Scott M. Plafker
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK
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Diagnosis, Mechanisms, and Differentiation of Inflammatory Diseases of the Outer Retina: Photoreceptoritis versus Choriocapillaritis; A Multimodal Imaging Perspective. Diagnostics (Basel) 2022; 12:diagnostics12092179. [PMID: 36140579 PMCID: PMC9497689 DOI: 10.3390/diagnostics12092179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/06/2022] [Accepted: 09/07/2022] [Indexed: 11/17/2022] Open
Abstract
Background and aim: Inflammatory diseases that affect the outer retina do so by different mechanisms. Some of them result from the direct, primary involvement of the outer retina (primary photoreceptoritis) such as acute zonal outer occult retinopathy (AZOOR). Others affect the photoreceptors secondarily due to the inflammatory involvement of the choriocapillaris. This results in choriocapillaris non-perfusion that damages the photoreceptors due to the ensuing ischaemia, a mechanism characterising primary inflammatory choriocapillaropathies (PICCPs) such as multiple evanescent white dot syndrome (MEWDS), idiopathic multifocal choroiditis (MFC), and others. Thanks to multimodal imaging (MMI), it is now possible to differentiate between these two mechanisms of outer retinal damage. The aim of this study is to determine the MMI characteristics that allow us to differentiate primary photoreceptoritis, including AZOOR, from PICCPs such as MEWDS and MFC. Methods: A series of eight PICCPs cases (five typical MEWDS and three typical active MFC cases) and four typical primary photoreceptoritis/AZOOR cases (five eyes) that had undergone complete MMI investigation, including fundus photography (FP), blue light fundus autofluorescence (BL-FAF), spectral domain optical coherence tomography (SD-OCT), OCT angiography (OCT-A, when available), fluorescein angiography (FA), and indocyanine green angiography (ICGA) were analysed, pointing out the differences that allow us to distinguish primary photoreceptoritis from PICCPs. Results: All primary photoreceptoritis/AZOOR cases showed (1) faint fundus pallor around the fovea, (2) BL-FAF hyperautofluorescence, (3) loss of photoreceptor outer segments (PROS) on SD-OCT, (4) absence of choriocapillary drop-out on OCT-A, (5) normal FA or faint FA hyperfluorescence, and (6) conserved ICGA fluorescence/no hypofluorescent areas; (1), (2), (3), and (5) indicated loss of photoreceptor outer segments, and (4) and (6) indicated conserved choriocapillaris circulation. For PICCPs, (a) fundus showed discreet white dots or none (in MEWDS) and punched-out scars in MFC, (b) BL-FAF hyperautofluorescence, (c) loss of PROS on SD-OCT, (d) FA faint hyperfluorescence in MEWDS, also minimal in active MFC lesions (e) in all cases ICGA hypofluorescent areas; (b) and (c) indicating loss of PROS, and (e) indicating choriocapillaris non-perfusion in all cases. The OCT-A did not show consistent findings with faint or no capillary drop-out in MEWDS and MFC. Conclusions: MMI combining the SD-OCT and BL-FAF clearly showed loss of PROS in both groups, while the ICGA determined whether this was due to choriocapillaris non-perfusion in PICCPs or whether the choriocapillaris was intact in case of primary photoreceptoritis. The FA and OCT-A were found to be less useful and/or less sensitive for the appraisal of both these entities.
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Zhang Y, Jeong H, Mori K, Ikeda SI, Shoda C, Miwa Y, Nakai A, Chen J, Ma Z, Jiang X, Torii H, Kubota Y, Negishi K, Kurihara T, Tsubota K. Vascular endothelial growth factor from retinal pigment epithelium is essential in choriocapillaris and axial length maintenance. PNAS NEXUS 2022; 1:pgac166. [PMID: 36714840 PMCID: PMC9802415 DOI: 10.1093/pnasnexus/pgac166] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 08/16/2022] [Indexed: 06/18/2023]
Abstract
Myopia, which prevalence is rapidly increasing, causes visual impairment; however, the onset mechanism of pathological axial length (AL) elongation remains unclear. A highly vascularized choroid between the retinal pigment epithelium (RPE) and sclera not only maintains physiological activities, but also contributes to ocular development and growth regulation. Vascular endothelial growth factor (VEGF) secreted from the RPE to the choroid is essential for retinal function and maintenance of the choriocapillaris. Herein, we demonstrated that the loss of VEGF secreted from the RPE caused abnormal choriocapillaris development and AL elongation, with features similar to those of the lens-induced myopia (LIM) mouse model, whereas VEGF overexpression by knocking-out von Hippel-Lindau (VHL) specific to the RPE expands the choriocapillaris and shortens the AL. Additionally, LDL Receptor Related Protein 2 (LRP2) deletion in the RPE downregulated VEGF expression and leads to pathological AL elongation. Furthermore, high-myopia patients without choriocapillaris demonstrated longer ALs than did those with preserved choriocapillaris. These results suggest that physiological secretion of VEGF from the RPE is required for proper AL development by maintaining the choriocapillaris. The pinpoint application of VEGF to the choriocapillaris may become a potential intervention for the prevention and treatment of axial myopia progression.
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Affiliation(s)
- Yan Zhang
- Laboratory of Photobiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Heonuk Jeong
- Laboratory of Photobiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Kiwako Mori
- Laboratory of Photobiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Shin-Ichi Ikeda
- Laboratory of Photobiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Chiho Shoda
- Laboratory of Photobiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Nihon University School of Medicine, 30-1 Oyaguchikamicho, Itabashi City, Tokyo 173-8610, Japan
| | - Yukihiro Miwa
- Laboratory of Photobiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Aichi Animal Eye Clinic, 3 Chome-17-3 Honjitori, Minami Ward, Nagoya, Aichi 457-0074, Japan
| | - Ayaka Nakai
- Laboratory of Photobiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Nihon University School of Medicine, 30-1 Oyaguchikamicho, Itabashi City, Tokyo 173-8610, Japan
| | - Junhan Chen
- Laboratory of Photobiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Ziyan Ma
- Laboratory of Photobiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Xiaoyan Jiang
- Laboratory of Photobiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Hidemasa Torii
- Laboratory of Photobiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Yoshiaki Kubota
- Department of Anatomy, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Kazuno Negishi
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Toshihide Kurihara
- Laboratory of Photobiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Tsubota Laboratory Inc., 34 Shinanomachi, 304 Toshin Shinanomachi Ekimae Building, Shinjuku-ku, Tokyo 160-0016, Japan
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Song X, Xu Q, Li H, Fan Q, Zheng Y, Zhang Q, Chu C, Zhang Z, Yuan C, Ning M, Bian C, Ma K, Qu Y. Automatic quantification of retinal photoreceptor integrity to predict persistent disease activity in neovascular age-related macular degeneration using deep learning. Front Neurosci 2022; 16:952735. [PMID: 36061600 PMCID: PMC9434346 DOI: 10.3389/fnins.2022.952735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/26/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose Using deep learning (DL)-based technique, we identify risk factors and create a prediction model for refractory neovascular age-related macular degeneration (nAMD) characterized by persistent disease activity (PDA) in spectral domain optical coherence tomography (SD-OCT) images. Materials and methods A total of 671 typical B-scans were collected from 186 eyes of 186 patients with nAMD. Spectral domain optical coherence tomography images were analyzed using a classification convolutional neural network (CNN) and a fully convolutional network (FCN) algorithm to extract six features involved in nAMD, including ellipsoid zone (EZ), external limiting membrane (ELM), intraretinal fluid (IRF), subretinal fluid (SRF), pigment epithelium detachment (PED), and subretinal hyperreflective material (SHRM). Random forest models were probed to predict 1-year disease activity (stable, PDA, and cured) based on the quantitative features computed from automated segmentation and evaluated with cross-validation. Results The algorithm to segment six SD-OCT features achieved the mean accuracy of 0.930 (95% CI: 0.916–0.943), dice coefficients of 0.873 (95% CI: 0.847–0.899), a sensitivity of 0.873 (95% CI: 0.844–0.910), and a specificity of 0.922 (95% CI: 0.905–0.940). The six-metric model including EZ and ELM achieved the optimal performance to predict 1-year disease activity, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.980, the accuracy of 0.930, the sensitivity of 0.920, and the specificity of 0.962. The integrity of EZ and ELM significantly improved the performance of the six-metric model than that of the four-metric model. Conclusion The prediction model reveals the potential to predict PDA in nAMD eyes. The integrity of EZ and ELM constituted the strongest predictive factor for PDA in nAMD eyes in real-world clinical practice. The results of this study are a significant step toward image-guided prediction of long-term disease activity in the management of nAMD and highlight the importance of the automatic identification of photoreceptor layers.
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Affiliation(s)
- Xian Song
- Department of Geriatrics, Qilu Hospital of Shandong University, Jinan, China
| | - Qian Xu
- Department of Geriatrics, Qilu Hospital of Shandong University, Jinan, China
| | - Haiming Li
- Department of Geriatrics, Qilu Hospital of Shandong University, Jinan, China
| | - Qian Fan
- Department of Geriatrics, Qilu Hospital of Shandong University, Jinan, China
| | | | | | | | | | | | | | - Cheng Bian
- Xiaohe Healthcare, ByteDance, Guangzhou, China
| | - Kai Ma
- Tencent Healthcare, Shenzhen, China
| | - Yi Qu
- Department of Geriatrics, Qilu Hospital of Shandong University, Jinan, China
- *Correspondence: Yi Qu,
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Henning Y, Blind US, Larafa S, Matschke J, Fandrey J. Hypoxia aggravates ferroptosis in RPE cells by promoting the Fenton reaction. Cell Death Dis 2022; 13:662. [PMID: 35906211 PMCID: PMC9338085 DOI: 10.1038/s41419-022-05121-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/15/2022] [Accepted: 07/20/2022] [Indexed: 01/21/2023]
Abstract
Oxidative stress and hypoxia in the retinal pigment epithelium (RPE) have long been considered major risk factors in the pathophysiology of age-related macular degeneration (AMD), but systematic investigation of the interplay between these two risk factors was lacking. For this purpose, we treated a human RPE cell line (ARPE-19) with sodium iodate (SI), an oxidative stress agent, together with dimethyloxalylglycine (DMOG) which leads to stabilization of hypoxia-inducible factors (HIFs), key regulators of cellular adaptation to hypoxic conditions. We found that HIF stabilization aggravated oxidative stress-induced cell death by SI and iron-dependent ferroptosis was identified as the main cell death mechanism. Ferroptotic cell death depends on the Fenton reaction where H2O2 and iron react to generate hydroxyl radicals which trigger lipid peroxidation. Our findings clearly provide evidence for superoxide dismutase (SOD) driven H2O2 production fostering the Fenton reaction as indicated by triggered SOD activity upon DMOG + SI treatment as well as by reduced cell death levels upon SOD2 knockdown. In addition, iron transporters involved in non-transferrin-bound Fe2+ import as well as intracellular iron levels were also upregulated. Consequently, chelation of Fe2+ by 2'2-Bipyridyl completely rescued cells. Taken together, we show for the first time that HIF stabilization under oxidative stress conditions aggravates ferroptotic cell death in RPE cells. Thus, our study provides a novel link between hypoxia, oxidative stress and iron metabolism in AMD pathophysiology. Since iron accumulation and altered iron metabolism are characteristic features of AMD retinas and RPE cells, our cell culture model is suitable for high-throughput screening of new treatment approaches against AMD.
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Affiliation(s)
- Yoshiyuki Henning
- grid.410718.b0000 0001 0262 7331Institute of Physiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Ursula Sarah Blind
- grid.410718.b0000 0001 0262 7331Institute of Physiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Safa Larafa
- grid.410718.b0000 0001 0262 7331Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Johann Matschke
- grid.410718.b0000 0001 0262 7331Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Joachim Fandrey
- grid.410718.b0000 0001 0262 7331Institute of Physiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
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Hazim RA, Paniagua AE, Tang L, Yang K, Kim KKO, Stiles L, Divakaruni AS, Williams DS. Vitamin B3, nicotinamide, enhances mitochondrial metabolism to promote differentiation of the retinal pigment epithelium. J Biol Chem 2022; 298:102286. [PMID: 35868562 PMCID: PMC9396405 DOI: 10.1016/j.jbc.2022.102286] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 01/04/2023] Open
Abstract
In the mammalian retina, a metabolic ecosystem exists in which photoreceptors acquire glucose from the choriocapillaris with the help of the retinal pigment epithelium (RPE). While the photoreceptor cells are primarily glycolytic, exhibiting Warburg-like metabolism, the RPE is reliant on mitochondrial respiration. However, the ways in which mitochondrial metabolism affect RPE cellular functions are not clear. We first used the human RPE cell line, ARPE-19, to examine mitochondrial metabolism in the context of cellular differentiation. We show that nicotinamide induced rapid differentiation of ARPE-19 cells, which was reversed by removal of supplemental nicotinamide. During the nicotinamide-induced differentiation, we observed using quantitative PCR, Western blotting, electron microscopy, and metabolic respiration and tracing assays that (1) mitochondrial gene and protein expression increased, (2) mitochondria became larger with more tightly folded cristae, and (3) mitochondrial metabolism was enhanced. In addition, we show that primary cultures of human fetal RPE cells responded similarly in the presence of nicotinamide. Furthermore, disruption of mitochondrial oxidation of pyruvate attenuated the nicotinamide-induced differentiation of the RPE cells. Together, our results demonstrate a remarkable effect of nicotinamide on RPE metabolism. We also identify mitochondrial respiration as a key contributor to the differentiated state of the RPE and thus to many of the RPE functions that are essential for retinal health and photoreception.
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Affiliation(s)
- Roni A Hazim
- Department of Ophthalmology and Stein Eye Institute
| | | | - Lisa Tang
- Department of Ophthalmology and Stein Eye Institute
| | - Krista Yang
- Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095
| | - Kristen K O Kim
- Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095
| | - Linsey Stiles
- Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095; Department of Medicine, Endocrinology. UCLA David Geffen School of Medicine. Los Angeles, CA, 90095, USA
| | - Ajit S Divakaruni
- Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095
| | - David S Williams
- Department of Ophthalmology and Stein Eye Institute; Department of Neurobiology, David Geffen School of Medicine at UCLA; Molecular Biology Institute; Brain Research Institute, University of California, Los Angeles, CA.
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Aparicio A, Camacho ET, Philp NJ, Wirkus SA. A mathematical model of GLUT1 modulation in rods and RPE and its differential impact in cell metabolism. Sci Rep 2022; 12:10645. [PMID: 35739198 PMCID: PMC9226191 DOI: 10.1038/s41598-022-13950-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 05/31/2022] [Indexed: 11/10/2022] Open
Abstract
We present a mathematical model of key glucose metabolic pathways in two cells of the human retina: the rods and the retinal pigmented epithelium (RPE). Computational simulations of glucose transporter 1 (GLUT1) inhibition in the model accurately reproduce experimental data from conditional knockout mice and reveal that modification of GLUT1 expression levels of both cells differentially impacts their metabolism. We hypothesize that, under glucose scarcity, the RPE's energy producing pathways are altered in order to preserve its functionality, impacting the photoreceptors' outer segment renewal. On the other hand, when glucose is limited in the rods, aerobic glycolysis is preserved, which maintains the lactate contribution to the RPE.
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Affiliation(s)
- Andrea Aparicio
- School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ, USA.
| | - Erika T Camacho
- School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ, USA
| | - Nancy J Philp
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Stephen A Wirkus
- School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ, USA
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Holubiec MI, Romero JI, Urbainsky C, Gellert M, Galeano P, Capani F, Lillig CH, Hanschmann EM. Nucleoredoxin Plays a Key Role in the Maintenance of Retinal Pigmented Epithelium Differentiation. Antioxidants (Basel) 2022; 11:antiox11061106. [PMID: 35740003 PMCID: PMC9220054 DOI: 10.3390/antiox11061106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/29/2022] [Accepted: 05/29/2022] [Indexed: 02/05/2023] Open
Abstract
Nucleoredoxin (Nrx) belongs to the Thioredoxin protein family and functions in redox-mediated signal transduction. It contains the dithiol active site motif Cys-Pro-Pro-Cys and interacts and regulates different proteins in distinct cellular pathways. Nrx was shown to be catalytically active in the insulin assay and recent findings indicate that Nrx functions, in fact, as oxidase. Here, we have analyzed Nrx in the mammalian retina exposed to (perinatal) hypoxia-ischemia/reoxygenation, combining ex vivo and in vitro models. Our data show that Nrx regulates cell differentiation, which is important to (i) increase the number of glial cells and (ii) replenish neurons that are lost following the hypoxic insult. Nrx is essential to maintain cell morphology. These regulatory changes are related to VEGF but do not seem to be linked to the Wnt/β-catenin pathway, which is not affected by Nrx knock-down. In conclusion, our results strongly suggest that hypoxia-ischemia could lead to alterations in the organization of the retina, related to changes in RPE cell differentiation. Nrx may play an essential role in the maintenance of the RPE cell differentiation state via the regulation of VEGF release.
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Affiliation(s)
- Mariana I. Holubiec
- Facultad de Medicina, Instituto de Investigaciones Cardiológicas “Prof. Dr. Alberto C. Taquini” (ININCA), Universidad de Buenos Aires (UBA-CONICET), Buenos Aires 1122, Argentina;
- Instituto de Investigación en Biomedicina de Buenos Aires, Partner Institute of the MaxPlank Society (IBioBA-CONICET-MPSP), Buenos Aires 2390, Argentina
- Correspondence: (M.I.H.); (E.-M.H.); Tel.: +54-11-51618547 (M.I.H.); +49-211-8106040 (E.-M.H.)
| | - Juan I. Romero
- Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), Fundación Instituto Leloir, Buenos Aires 1405, Argentina; (J.I.R.); (P.G.)
| | - Claudia Urbainsky
- Institute for Medical Biochemistry and Molecular Biology, University Medicine Greifswald, University of Greifswald, 17489 Greifswald, Germany; (C.U.); (M.G.); (C.H.L.)
| | - Manuela Gellert
- Institute for Medical Biochemistry and Molecular Biology, University Medicine Greifswald, University of Greifswald, 17489 Greifswald, Germany; (C.U.); (M.G.); (C.H.L.)
| | - Pablo Galeano
- Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), Fundación Instituto Leloir, Buenos Aires 1405, Argentina; (J.I.R.); (P.G.)
| | - Francisco Capani
- Facultad de Medicina, Instituto de Investigaciones Cardiológicas “Prof. Dr. Alberto C. Taquini” (ININCA), Universidad de Buenos Aires (UBA-CONICET), Buenos Aires 1122, Argentina;
- Facultad de Medicina, Universidad Católica Argentina (UCA), Buenos Aires 1600, Argentina
| | - Christopher Horst Lillig
- Institute for Medical Biochemistry and Molecular Biology, University Medicine Greifswald, University of Greifswald, 17489 Greifswald, Germany; (C.U.); (M.G.); (C.H.L.)
| | - Eva-Maria Hanschmann
- Institute for Medical Biochemistry and Molecular Biology, University Medicine Greifswald, University of Greifswald, 17489 Greifswald, Germany; (C.U.); (M.G.); (C.H.L.)
- Department of Neurology, Medical Faculty, Heinrich-Heine University, 40225 Düsseldorf, Germany
- Correspondence: (M.I.H.); (E.-M.H.); Tel.: +54-11-51618547 (M.I.H.); +49-211-8106040 (E.-M.H.)
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40
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Hanna J, David LA, Touahri Y, Fleming T, Screaton RA, Schuurmans C. Beyond Genetics: The Role of Metabolism in Photoreceptor Survival, Development and Repair. Front Cell Dev Biol 2022; 10:887764. [PMID: 35663397 PMCID: PMC9157592 DOI: 10.3389/fcell.2022.887764] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 04/19/2022] [Indexed: 12/11/2022] Open
Abstract
Vision commences in the retina with rod and cone photoreceptors that detect and convert light to electrical signals. The irreversible loss of photoreceptors due to neurodegenerative disease leads to visual impairment and blindness. Interventions now in development include transplanting photoreceptors, committed photoreceptor precursors, or retinal pigment epithelial (RPE) cells, with the latter protecting photoreceptors from dying. However, introducing exogenous human cells in a clinical setting faces both regulatory and supply chain hurdles. Recent work has shown that abnormalities in central cell metabolism pathways are an underlying feature of most neurodegenerative disorders, including those in the retina. Reversal of key metabolic alterations to drive retinal repair thus represents a novel strategy to treat vision loss based on cell regeneration. Here, we review the connection between photoreceptor degeneration and alterations in cell metabolism, along with new insights into how metabolic reprogramming drives both retinal development and repair following damage. The potential impact of metabolic reprogramming on retinal regeneration is also discussed, specifically in the context of how metabolic switches drive both retinal development and the activation of retinal glial cells known as Müller glia. Müller glia display latent regenerative properties in teleost fish, however, their capacity to regenerate new photoreceptors has been lost in mammals. Thus, re-activating the regenerative properties of Müller glia in mammals represents an exciting new area that integrates research into developmental cues, central metabolism, disease mechanisms, and glial cell biology. In addition, we discuss this work in relation to the latest insights gleaned from other tissues (brain, muscle) and regenerative species (zebrafish).
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Affiliation(s)
- Joseph Hanna
- Sunnybrook Research Institute, Biological Sciences, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
| | - Luke Ajay David
- Sunnybrook Research Institute, Biological Sciences, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
| | - Yacine Touahri
- Sunnybrook Research Institute, Biological Sciences, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Taylor Fleming
- Sunnybrook Research Institute, Biological Sciences, Toronto, ON, Canada
| | - Robert A. Screaton
- Sunnybrook Research Institute, Biological Sciences, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Carol Schuurmans
- Sunnybrook Research Institute, Biological Sciences, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- *Correspondence: Carol Schuurmans,
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41
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Tang H, Kong L, Yang Y, Li J, Zou H. Puerarin suppresses hypoxia-induced vascular endothelial growth factor upregulation in human retinal pigmented epithelial cells by blocking JAK2/STAT3 pathway. Bioengineered 2022; 13:11636-11645. [PMID: 35510332 PMCID: PMC9275891 DOI: 10.1080/21655979.2022.2070586] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The purpose of this study was to explore the mechanism by which puerarin regulated the expression of hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor (VEGF) in humans' retinal pigment epithelial (RPE) cells under hypoxia. RPE cells (ARPE-19 and D407 cells) and a rat model of oxygen-induced retinopathy were used in the current study. Western blotting and ELISA were performed to detect the level of JAK2, phosphorylated JAK2, STAT3, phosphorylated STAT3, HIF-1α, and VEGF in cells. In addition, the interaction between JAK2 and STAT3 was determined using with a co-immunoprecipitation assay. We found puerarin inhibited hypoxia-induced upregulation of VEGF at both the mRNA and protein level via decreasing HIF-1α expression in RPE cells. Moreover, puerarin attenuated the interaction between JAK2 and STAT3, and subsequently blocking p-STAT3 nucleus translocation in vitro and in vivo. In conclusion, puerarin could effectively inhibit hypoxia-induced VEGF upregulation in RPE cells via mediated JAK2/STAT3 pathway.
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Affiliation(s)
- Huixin Tang
- Department of Ophthalmology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai China
| | - Lingchun Kong
- Department of Ophthalmology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai China
| | - Yuqin Yang
- Department of Ophthalmology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai China
| | - Jingjing Li
- Department of Ophthalmology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai China
| | - Hong Zou
- Department of Ophthalmology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai China
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42
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Peters F, Ebner LJA, Atac D, Maggi J, Berger W, den Hollander AI, Grimm C. Regulation of ABCA1 by AMD-Associated Genetic Variants and Hypoxia in iPSC-RPE. Int J Mol Sci 2022; 23:ijms23063194. [PMID: 35328615 PMCID: PMC8953808 DOI: 10.3390/ijms23063194] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 02/04/2023] Open
Abstract
Age-related macular degeneration (AMD) is a progressive disease of the macula characterized by atrophy of the retinal pigment epithelium (RPE) and photoreceptor degeneration, leading to severe vision loss at advanced stages in the elderly population. Impaired reverse cholesterol transport (RCT) as well as intracellular lipid accumulation in the RPE are implicated in AMD pathogenesis. Here, we focus on ATP-binding cassette transporter A1 (ABCA1), a major cholesterol transport protein in the RPE, and analyze conditions that lead to ABCA1 dysregulation in induced pluripotent stem cell (iPSC)-derived RPE cells (iRPEs). Our results indicate that the risk-conferring alleles rs1883025 (C) and rs2740488 (A) in ABCA1 are associated with increased ABCA1 mRNA and protein levels and reduced efficiency of cholesterol efflux from the RPE. Hypoxia, an environmental risk factor for AMD, reduced expression of ABCA1 and increased intracellular lipid accumulation. Treatment with a liver X receptor (LXR) agonist led to an increase in ABCA1 expression and reduced lipid accumulation. Our data strengthen the homeostatic role of cholesterol efflux in the RPE and suggest that increasing cellular cholesterol export by stimulating ABCA1 expression might lessen lipid load, improving RPE survival and reducing the risk of developing AMD.
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Affiliation(s)
- Florian Peters
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8952 Zurich, Switzerland;
- Correspondence: (F.P.); (C.G.)
| | - Lynn J. A. Ebner
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8952 Zurich, Switzerland;
| | - David Atac
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Zurich, Switzerland; (D.A.); (J.M.); (W.B.)
| | - Jordi Maggi
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Zurich, Switzerland; (D.A.); (J.M.); (W.B.)
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Zurich, Switzerland; (D.A.); (J.M.); (W.B.)
| | - Anneke I. den Hollander
- Department of Ophthalmology, Radboud University Medical Center, 6525 Nijmegen, The Netherlands;
- AbbVie, Genomic Research Center, 200 Sidney Street, Cambridge, MA 02139, USA
| | - Christian Grimm
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8952 Zurich, Switzerland;
- Correspondence: (F.P.); (C.G.)
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43
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Yazdani M. Uncontrolled Oxygen Levels in Cultures of Retinal Pigment Epithelium: Have We Missed the Obvious? Curr Eye Res 2022; 47:651-660. [PMID: 35243933 DOI: 10.1080/02713683.2022.2050264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Retinal pigment epithelium (RPE) is the outermost layer of retina located between the photoreceptor cells and the choroid. This highly-polarized monolayer provides critical support for the functioning of the other parts of the retina, especially photoreceptors. Methods of culturing RPE have been under development since its establishment in 1920s. Despite considering various factors, oxygen (O2) levels in RPE microenvironments during culture preparation and experimental procedure have been overlooked. O2 is a crucial parameter in the cultures, and therefore, maintaining RPE cells at O2 levels different from their native environment (70-90 mm Hg of O2) could have unintended consequences. Owing to the importance of the topic, lack of sufficient discussion in the literature and to encourage future research, this paper will focus on uncontrolled O2 level in cultures of RPE cells.
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Affiliation(s)
- Mazyar Yazdani
- Department of Medical Biochemistry, Oslo University Hospital, Rikshospitalet, 0027 Oslo, Norway
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44
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OUP accepted manuscript. J Pharm Pharmacol 2022; 74:1689-1699. [DOI: 10.1093/jpp/rgac036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 07/18/2022] [Indexed: 11/13/2022]
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45
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Shinojima A, Lee D, Tsubota K, Negishi K, Kurihara T. Retinal Diseases Regulated by Hypoxia-Basic and Clinical Perspectives: A Comprehensive Review. J Clin Med 2021; 10:jcm10235496. [PMID: 34884197 PMCID: PMC8658588 DOI: 10.3390/jcm10235496] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/08/2021] [Accepted: 11/19/2021] [Indexed: 11/16/2022] Open
Abstract
In recent years, the number of patients with age-related macular degeneration (AMD) is increasing worldwide along with increased life expectancy. Currently, the standard treatment for wet-AMD is intravitreal injection of anti-vascular endothelial growth factor (VEGF) drugs. The upstream of VEGF is hypoxia-inducible factor (HIF), a master regulator of hypoxia-responsive genes responsive to acute and chronic hypoxia. HIF activation induces various pathological pro-angiogenic gene expressions including VEGF under retinal hypoxia, ultimately leading to the development of ocular ischemic neovascular diseases. In this regard, HIF is considered as a promising therapeutic target in ocular ischemic diseases. In clinical ophthalmology, abnormal hypofluorescent areas have been detected in the late-phase of indocyanine green angiography, which are thought to be lipid deposits at the level of Bruch’s membrane to choriocapillaris in vitreoretinal diseases. These deposits may interfere with the oxygen and nutrients that should be supplied to the retinal pigment epithelium, and that HIF/VEGF is highly suspected to be expressed in the hypoxic retinal pigment epithelium, leading to neovascularization. In this review, we comprehensively summarize pathophysiology of AMD-related ocular diseases with the HIF/VEGF pathway from basic and clinic researches with recent findings.
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Affiliation(s)
- Ari Shinojima
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.S.); (D.L.)
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (K.T.); (K.N.)
| | - Deokho Lee
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.S.); (D.L.)
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (K.T.); (K.N.)
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (K.T.); (K.N.)
- Tsubota Laboratory, Inc., Tokyo 160-0016, Japan
| | - Kazuno Negishi
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (K.T.); (K.N.)
| | - Toshihide Kurihara
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.S.); (D.L.)
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (K.T.); (K.N.)
- Correspondence: ; Tel.: +81-3-5313-4132; Fax: +81-3-5363-3274
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46
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Tsantilas KA, Cleghorn WM, Bisbach CM, Whitson JA, Hass DT, Robbings BM, Sadilek M, Linton JD, Rountree AM, Valencia AP, Sweetwyne MT, Campbell MD, Zhang H, Jankowski CSR, Sweet IR, Marcinek DJ, Rabinovitch PS, Hurley JB. An Analysis of Metabolic Changes in the Retina and Retinal Pigment Epithelium of Aging Mice. Invest Ophthalmol Vis Sci 2021; 62:20. [PMID: 34797906 PMCID: PMC8606884 DOI: 10.1167/iovs.62.14.20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Purpose The purpose of this study was to present our hypothesis that aging alters metabolic function in ocular tissues. We tested the hypothesis by measuring metabolism in aged murine tissues alongside retinal responses to light. Methods Scotopic and photopic electroretinogram (ERG) responses in young (3–6 months) and aged (23–26 months) C57Bl/6J mice were recorded. Metabolic flux in retina and eyecup explants was quantified using U-13C-glucose or U-13C-glutamine with gas chromatography-mass spectrometry (GC-MS), O2 consumption rate (OCR) in a perifusion apparatus, and quantifying adenosine triphosphatase (ATP) with a bioluminescence assay. Results Scotopic and photopic ERG responses were reduced in aged mice. Glucose metabolism, glutamine metabolism, OCR, and ATP pools in retinal explants were mostly unaffected in aged mice. In eyecups, glutamine usage in the Krebs Cycle decreased while glucose metabolism, OCR, and ATP pools remained stable. Conclusions Our examination of metabolism showed negligible impact of age on retina and an impairment of glutamine anaplerosis in eyecups. The metabolic stability of these tissues ex vivo suggests age-related metabolic alterations may not be intrinsic. Future experiments should focus on determining whether external factors including nutrient supply, oxygen availability, or structural changes influence ocular metabolism in vivo.
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Affiliation(s)
- Kristine A Tsantilas
- Department of Biochemistry, University of Washington, Seattle, Washington, United States
| | - Whitney M Cleghorn
- Department of Biochemistry, University of Washington, Seattle, Washington, United States
| | - Celia M Bisbach
- Department of Biochemistry, University of Washington, Seattle, Washington, United States
| | - Jeremy A Whitson
- Department of Biology, Davidson College, Davidson, North Carolina, United States
| | - Daniel T Hass
- Department of Biochemistry, University of Washington, Seattle, Washington, United States
| | - Brian M Robbings
- Department of Biochemistry, University of Washington, Seattle, Washington, United States.,UW Diabetes Institute, University of Washington, Seattle, Washington, United States
| | - Martin Sadilek
- Department of Chemistry, University of Washington, Seattle, Washington, United States
| | - Jonathan D Linton
- Department of Biochemistry, University of Washington, Seattle, Washington, United States
| | - Austin M Rountree
- UW Diabetes Institute, University of Washington, Seattle, Washington, United States
| | - Ana P Valencia
- Department of Radiology, University of Washington, Seattle, Washington, United States
| | - Mariya T Sweetwyne
- Department of Laboratory Medicine & Pathology, University of Washington, Seattle, Washington, United States
| | - Matthew D Campbell
- Department of Radiology, University of Washington, Seattle, Washington, United States
| | - Huiliang Zhang
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
| | - Connor S R Jankowski
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States.,Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States
| | - Ian R Sweet
- UW Diabetes Institute, University of Washington, Seattle, Washington, United States
| | - David J Marcinek
- Department of Radiology, University of Washington, Seattle, Washington, United States
| | - Peter S Rabinovitch
- Department of Laboratory Medicine & Pathology, University of Washington, Seattle, Washington, United States
| | - James B Hurley
- Department of Biochemistry, University of Washington, Seattle, Washington, United States.,Department of Ophthalmology, University of Washington, Seattle, Washington, United States
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47
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Qiu Q, Lv P, Zhongshen Y, Yuan F, Zhang X, Zhou X, Li S, Liu X, Zhang J. Electrophysiological mechanisms underlying hypoxia-induced deficits in visual spatial and non-spatial discrimination. Physiol Rep 2021; 9:e15036. [PMID: 34558212 PMCID: PMC8461214 DOI: 10.14814/phy2.15036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 08/19/2021] [Accepted: 08/23/2021] [Indexed: 12/16/2022] Open
Abstract
Impaired visual cognition in residents of hypoxic environment has been widely reported; however, the underlying electrophysiological mechanisms remain unclear. In this study, 23 college students underwent three sessions of a Clock task test before a 30-day high-altitude exposure (Test 1) and 1 week (Test 2) and 3 months (Test 3) after they returned to lowlands. The Clock task consists of a visual spatial angle and a visual non-spatial color discrimination subtask. Simultaneously, electroencephalography (EEG) was recorded during the Clock task. The behavioral results showed that, compared with Test 1, accuracy in Test 2 was significantly decreased in both the Angle and Color tasks, and reaction time (RT) was significantly increased in the Angle task. The event-related potentials results showed that, during both tasks amplitudes of the occipital N1 and P3 components during both tasks were significantly decreased in Test 2, compared with Test 1. Moreover, N1 amplitude was negatively correlated with RT and positively correlated with accuracy. Further time-frequency EEG analysis showed that theta power at occipital sites was significantly decreased in both tasks in Test 2, compared with Test 1, and was negatively correlated with RT in the Angle task. In Test 3, both the behavioral performance and EEG activity recovered to the baseline level in Test 1. These findings suggested that hypoxia impairs both visual spatial and visual non-spatial discriminations, and these impairments can recover after subjects return to lowlands. Inhibition of brain electrophysiological activity in the visual cortex may explain the deficits in visual cognition.
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Affiliation(s)
- Qi Qiu
- Institute of Brain Diseases and CognitionSchool of MedicineXiamen UniversityXiamenFujianChina
| | - Pengpeng Lv
- Department of Clinical MedicineSchool of MedicineXiamen UniversityXiamenFujianChina
| | - Yihao Zhongshen
- Department of Traditional Chinese MedicineSchool of MedicineXiamen UniversityXiamenFujianChina
| | - Fengjuan Yuan
- Institute of Brain Diseases and CognitionSchool of MedicineXiamen UniversityXiamenFujianChina
| | - Xinjuan Zhang
- Institute of Brain Diseases and CognitionSchool of MedicineXiamen UniversityXiamenFujianChina
| | - Xiuzhu Zhou
- Department of Gynecology and ObstetricsThe First Affiliated Hospital of Xiamen UniversityXiamenFujianChina
| | - Shanhua Li
- Institute of Brain Diseases and CognitionSchool of MedicineXiamen UniversityXiamenFujianChina
| | - Xiaonan Liu
- Institute of PsychologySchool of Public PolicyXiamen UniversityXiamenFujianChina
| | - Jiaxing Zhang
- Institute of Brain Diseases and CognitionSchool of MedicineXiamen UniversityXiamenFujianChina
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48
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Kunimi H, Lee D, Ibuki M, Katada Y, Negishi K, Tsubota K, Kurihara T. Inhibition of the HIF-1α/BNIP3 pathway has a retinal neuroprotective effect. FASEB J 2021; 35:e21829. [PMID: 34314069 DOI: 10.1096/fj.202100572r] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 07/01/2021] [Accepted: 07/16/2021] [Indexed: 12/15/2022]
Abstract
Retinal ischemia is a leading cause of irreversible blindness worldwide. Inner retinal dysfunction including loss of retinal ganglion cells is encountered in a number of retinal ischemic disorders. We previously reported administration of two different hypoxia-inducible factor (HIF) inhibitors exerted neuroprotective effects in a murine model of retinal ischemia/reperfusion (I/R) which mimics these disorders, as inner retinal degeneration could be involved in pathological HIF induction. However, this notion needs further investigation. Therefore, in this study, we attempted to use retina-specific Hif-1α conditional knockout (cKO) mice to uncover this notion more clearly under the same condition. Hif-1α cKO mice showed inner retinal neurodegeneration to a lesser extent than control mice. Hif-1α depletion in a murine 661W retinal cell line reduced cell death under pseudohypoxic and hypoxic conditions. Among hypoxia-related genes, the expression of BCL2 19 kDa protein-interacting protein 3 (Bnip3) was substantially upregulated in the inner retinal layer after retinal I/R. In this regard, we further examined Bnip3 depletion in retinal neurons in vitro and in vivo and found the similar neuroprotective effects. Our results support the notion that the HIF-1α/BNIP3 pathway may have a critical role in inner retinal neurodegeneration, which can be linked with the development of new promising therapeutics for inner retinal ischemic disorders.
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Affiliation(s)
- Hiromitsu Kunimi
- Laboratory of Photobiology, Keio University School of Medicine, Shinanomachi, Japan.,Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Japan
| | - Deokho Lee
- Laboratory of Photobiology, Keio University School of Medicine, Shinanomachi, Japan.,Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Japan
| | - Mari Ibuki
- Laboratory of Photobiology, Keio University School of Medicine, Shinanomachi, Japan.,Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Japan
| | - Yusaku Katada
- Laboratory of Photobiology, Keio University School of Medicine, Shinanomachi, Japan.,Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Japan
| | - Kazuno Negishi
- Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Japan
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Japan.,Tsubota Laboratory, Inc., Tokyo, Japan
| | - Toshihide Kurihara
- Laboratory of Photobiology, Keio University School of Medicine, Shinanomachi, Japan.,Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Japan
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49
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Xu B, Zhou L, Chen Q, Zhang J, Huang L, Wang S, Ye Z, Ren X, Cai Y, Jensen LD, Chen W, Li X, Ju R. Role of VEGFR2 in Mediating Endoplasmic Reticulum Stress Under Glucose Deprivation and Determining Cell Death, Oxidative Stress, and Inflammatory Factor Expression. Front Cell Dev Biol 2021; 9:631413. [PMID: 34222224 PMCID: PMC8249873 DOI: 10.3389/fcell.2021.631413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 03/24/2021] [Indexed: 11/13/2022] Open
Abstract
Retinal pigment epithelium (RPE), a postmitotic monolayer located between the neuroretina and choroid, supports the retina and is closely associated with vision loss diseases such as age-related macular degeneration (AMD) upon dysfunction. Although environmental stresses are known to play critical roles in AMD pathogenesis and the roles of other stresses have been well investigated, glucose deprivation, which can arise from choriocapillary flow voids, has yet to be fully explored. In this study, we examined the involvement of VEGFR2 in glucose deprivation-mediated cell death and the underlying mechanisms. We found that VEGFR2 levels are a determinant for RPE cell death, a critical factor for dry AMD, under glucose deprivation. RNA sequencing analysis showed that upon VEGFR2 knockdown under glucose starvation, endoplasmic reticulum (ER) stress and unfolded protein response (UPR) are reduced. Consistently, VEGFR2 overexpression increased ER stress under the same condition. Although VEGFR2 was less expressed compared to EGFR1 and c-Met in RPE cells, it could elicit a higher level of ER stress induced by glucose starvation. Finally, downregulated VEGFR2 attenuated the oxidative stress and inflammatory factor expression, two downstream targets of ER stress. Our study, for the first time, has demonstrated a novel role of VEGFR2 in RPE cells under glucose deprivation, thus providing valuable insights into the mechanisms of AMD pathogenesis and suggesting that VEGFR2 might be a potential therapeutic target for AMD prevention, which may impede its progression.
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Affiliation(s)
- Bohan Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Linbin Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qishan Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jianing Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Lijuan Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shasha Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Zhimin Ye
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiangrong Ren
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yu Cai
- Chengdu Aier Eye Hospital, Chengdu, China
| | - Lasse Dahl Jensen
- Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Weirong Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xuri Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Rong Ju
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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Abstract
The outer retina is nourished from the choroid, a capillary bed just inside the sclera. O2, glucose, and other nutrients diffuse out of the choroid and then filter through a monolayer of retinal pigment epithelium (RPE) cells to fuel the retina. Recent studies of energy metabolism have revealed striking differences between retinas and RPE cells in the ways that they extract energy from fuels. The purpose of this review is to suggest and evaluate the hypothesis that the retina and RPE have complementary metabolic roles that make them depend on each other for survival and for their abilities to perform essential and specialized functions. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- James B Hurley
- Departments of Biochemistry and Ophthalmology, University of Washington, Seattle, Washington 98115, USA;
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